docs: update documentation files and fix linting issues

README.md

@@ -62,8 +62,11 @@ beta_shape_pnpi/
 │       │   ├── exchange.py              ✓ Hayen-2018 empirical fit coefficients
 │       │   ├── radiative.py             ✓ Outer radiative corrections, soft-photon resummation
 │       │   └── detector_response.py     ✓ Analytical detector response models
-├── beta_spectrum/visualize/ ← plotting / visualization
+├── beta_spectrum/output/    ← output, plotting, visualization, CSV export
-│   └── __init__.py          # BetaSpectrumAnalyzer
+│   ├── __init__.py          # BetaSpectrumAnalyzer, CSVEmitter, Visualizer
+│   ├── core.py              # BetaSpectrumAnalyzer base class
+│   ├── csv_export.py        # CSV export functionality
+│   └── visualization.py     # Plotting and visualization functionality
 ├── exp_data/                ← experimental data handling
 │   ├── __init__.py          # ExpSpectrum, EnergyCalibrator, GaussianFitter, etc.
 │   ├── spectrum.py          # ExpSpectrum dataclass (energies, counts, errors, metadata)
@@ -117,7 +120,7 @@ Defined in `beta_spectrum/spectrum.py`. Orchestrates the calculation:
 
 ### `BetaSpectrumAnalyzer`
 
-In `beta_spectrum.visualize`. Provides debugging and visualization tools:
+In `beta_spectrum.output`. Provides debugging and visualization tools:
 
 - `total_spectrum(normalize=True/False)` — computed spectrum array
 - `plot_analysis(save_path=None, show_components=True)` — plot with two modes:
@@ -133,7 +136,7 @@ ______________________________________________________________________
 
 ```python
 from beta_spectrum import SpectrumConfig, BetaSpectrum
-from beta_spectrum.visualize import BetaSpectrumAnalyzer
+from beta_spectrum.output import BetaSpectrumAnalyzer
 
 config = SpectrumConfig(
     Z_parent=90,       # Thorium-232 (example)

TODO.md

@@ -51,8 +51,11 @@ fitter/                     ← main analysis framework
 ├── result.py               ← FitResult, analysis results
 # └── report.py               ← PDF report generation (deferred)
 
-visualize/                  ← visualization / plotting
+output/                     ← output, visualization, CSV export
-└── visualize/__init__.py   ← BetaSpectrumAnalyzer
+├── __init__.py             ← BetaSpectrumAnalyzer, CSVEmitter, Visualizer
+├── core.py                 ← BetaSpectrumAnalyzer base class
+├── csv_export.py           ← CSV export functionality
+└── visualization.py        ← Plotting and visualization functionality
 ```
 
 ### Rationale
@@ -64,6 +67,7 @@ visualize/                  ← visualization / plotting
 ### Migration Plan
 
 #### Phase 1: Create `exp_data` module ✅ COMPLETE
+
 - [x] `exp_data/spectrum.py` — `ExpSpectrum` dataclass: energies, counts, errors, metadata
 - [x] `exp_data/calibration.py` — `EnergyCalibrator` + `CalibrationResult`: linear/quadratic channel→energy
 - [x] `exp_data/fitters.py` — `GaussianFitter` + `PeakFitter`: peak detection and fitting
@@ -71,6 +75,7 @@ visualize/                  ← visualization / plotting
 - [x] 43 tests, ruff + mypy clean
 
 #### Phase 2: Create `fitter` module ✅ COMPLETE
+
 - [x] `fitter/model.py` — `SpectrumModel`: wraps `BetaSpectrum` + `DetectorResponse`, callable model with convolution
 - [x] `fitter/fit_engine.py` — `SpectrumFitter` + `FitConfig` + `FitResult`: χ² fitting, covariance, profile likelihood, confidence intervals
 - [x] `fitter/extractor.py` — `CWExtractor` + `GVAExtractor`: C(W) and g_V/g_A extraction
@@ -79,6 +84,7 @@ visualize/                  ← visualization / plotting
 - [x] Detector convolution handles W < 1.0 edge cases
 
 #### Phase 3: Clean up `beta_spectrum` ✅ COMPLETE
+
 - [x] Remove `cw_extractor.py` (moved to `fitter/extractor.py`)
 - [x] Remove `fitter.py` (moved to `fitter/fit_engine.py`)
 - [x] Clean up `__init__.py` — only exports theory classes
@@ -88,6 +94,7 @@ visualize/                  ← visualization / plotting
 - [x] 322 tests pass, ruff + mypy clean on all 26 source files
 
 #### Phase 4: Update package structure ✅ COMPLETE
+
 - [x] `pyproject.toml` auto-discovers all 4 packages via `setuptools.packages.find`
 - [x] `beta_spectrum.cli` keeps CLI entry point (no re-exports needed)
 - [x] All imports updated across 26 source files
@@ -313,6 +320,7 @@ ______________________________________________________________________
 **Version:** 0.3.1 → **In progress: 0.4.0 — Package restructuring**
 
 ### Completed (v0.3.x)
+
 - All theoretical corrections: phase space, Fermi function, finite size, screening, exchange, radiative (with delta_cut resummation)
 - Detector response module with analytical models (Gaussian, Gaussian+tail, Tikhonov), convolution API
 - χ² curve fitting framework (CurveFitter) with confidence intervals, profile likelihood, correlation analysis
@@ -327,20 +335,22 @@ ______________________________________________________________________
 - Plot output: unified multi-branch approach, externalized headers, compact legends, consistent titles
 
 ### Completed (v0.4.0)
+
 - **Track B: Package restructuring** — separating into `beta_spectrum` (theory), `exp_data` (experimental data), `fitter` (analysis framework)
   - [x] Phase 1: Create `exp_data` module (raw_data.py, calibration.py, fitters.py, corrections.py, spectrum.py) — 43 tests
   - [x] Phase 2: Create `fitter` module (model.py, fit_engine.py, extractor.py, result.py) — 34 tests
-  - [x] Phase 3: Clean up `beta_spectrum` (remove cw_extractor.py, fitter.py, __init__.py cleanup) — 322 tests
+  - [x] Phase 3: Clean up `beta_spectrum` (remove cw_extractor.py, fitter.py, **init**.py cleanup) — 322 tests
   - [x] Phase 4: Package auto-discovered by setuptools, all imports updated, black formatting applied
 - **v0.4.0 is COMPLETE**
   - 322 tests pass (262 original + 60 new)
   - ruff + mypy clean on all 26 source files
   - black formatting applied to all new code
-  - `pyproject.toml` auto-discovers all 4 packages: `beta_spectrum`, `beta_spectrum.visualize`, `exp_data`, `fitter`
+  - `pyproject.toml` auto-discovers all 4 packages: `beta_spectrum`, `beta_spectrum.output`, `exp_data`, `fitter`
   - README updated with new architecture diagram and Quick Start examples
   - Version bumped to 0.4.0
 
 ### Next Immediate Step
+
 - **Track A: ⁹⁹Tc spectrum-shape analysis** — start real data processing pipeline
   - Data processing pipeline for experimental runs
   - Endpoint fitting and energy calibration

exp_data/calibration.py

@@ -395,8 +395,6 @@ class EnergyCalibrator:
                 if best_pair is not None:
                     ch_low, ch_high = best_pair
                     e_min, e_max = min(known_energies), max(known_energies)
-                    gain = (ch_high - ch_low) / (e_max - e_min)
-                    intercept = ch_low - gain * e_min
                     channel_to_energy[float(ch_low)] = e_min
                     channel_to_energy[float(ch_high)] = e_max
 

notebooks/01-beta-spectrum-calculator.ipynb

@@ -42,15 +42,8 @@
     "    BranchConfig,\n",
     "    BetaSpectrumAnalyzer,\n",
     "    PhaseSpace,\n",
-    "    FermiFunction,\n",
-    "    FiniteSizeL0,\n",
-    "    ChargeDistributionU,\n",
-    "    ScreeningCorrection,\n",
-    "    ExchangeCorrection,\n",
-    "    RadiativeCorrection,\n",
     "    T_to_W,\n",
     "    W_to_T,\n",
-    "    momentum,\n",
     "    ME_MEV,\n",
     ")\n",
     "\n",

notebooks/exp_calibration.ipynb

@@ -21,7 +21,6 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "import matplotlib\n",
     "# Use non-interactive backend only when no display is available (e.g. jupyter execute)\n",
     "import matplotlib as mpl\n",
     "try:\n",

scripts/docs_check.py

@@ -12,20 +12,18 @@ Exit codes:
 """
 
 import argparse
-import json
 import os
 import re
 import subprocess
 import sys
 from dataclasses import dataclass, field
 from pathlib import Path
-from typing import Optional
-
 
 # ---------------------------------------------------------------------------
 # Types
 # ---------------------------------------------------------------------------
 
+
 @dataclass
 class Finding:
     severity: str  # "ERROR" | "WARN" | "INFO"
@@ -82,9 +80,20 @@ def all_source_files() -> list[Path]:
     """Walk the source tree and return all .py files."""
     files = []
     for root, dirs, filenames in os.walk(ROOT):
-        dirs[:] = [d for d in dirs if not d.startswith(".")
+        dirs[:] = [
-                   and d not in ("__pycache__", ".pytest_cache", ".mypy_cache",
+            d
-                                 ".ruff_cache", ".hypothesis", ".ipynb_checkpoints")]
+            for d in dirs
+            if not d.startswith(".")
+            and d
+            not in (
+                "__pycache__",
+                ".pytest_cache",
+                ".mypy_cache",
+                ".ruff_cache",
+                ".hypothesis",
+                ".ipynb_checkpoints",
+            )
+        ]
         if "egg-info" in root:
             continue
         for fn in filenames:
@@ -97,6 +106,7 @@ def all_source_files() -> list[Path]:
 # Checks
 # ---------------------------------------------------------------------------
 
+
 def check_version_consistency(report: Report):
     """Check that __version__ matches pyproject.toml version."""
     pyproject = ROOT / "pyproject.toml"
@@ -116,8 +126,12 @@ def check_version_consistency(report: Report):
             ver = ver_match.group(1)
             if ver != py_ver:
                 rel = pyfile.relative_to(ROOT)
-                report.add("ERROR", rel.name, "version",
+                report.add(
-                           f"__version__ = '{ver}' but pyproject.toml says '{py_ver}'")
+                    "ERROR",
+                    rel.name,
+                    "version",
+                    f"__version__ = '{ver}' but pyproject.toml says '{py_ver}'",
+                )
 
 
 def check_version_in_code(report: Report):
@@ -134,16 +148,19 @@ def check_version_in_code(report: Report):
 
     try:
         result = subprocess.run(
-            ["bs_pnpi", "--version"],
+            ["bs_pnpi", "--version"], capture_output=True, text=True, timeout=10
-            capture_output=True, text=True, timeout=10
         )
         if result.returncode == 0:
-            cli_ver_match = re.search(r'(\d+\.\d+\.\d+)', result.stdout)
+            cli_ver_match = re.search(r"(\d+\.\d+\.\d+)", result.stdout)
             if cli_ver_match:
                 cli_ver = cli_ver_match.group(1)
                 if cli_ver != py_ver:
-                    report.add("ERROR", "cli", "version",
+                    report.add(
-                               f"CLI reports version '{cli_ver}' but pyproject.toml says '{py_ver}'")
+                        "ERROR",
+                        "cli",
+                        "version",
+                        f"CLI reports version '{cli_ver}' but pyproject.toml says '{py_ver}'",
+                    )
     except (subprocess.TimeoutExpired, FileNotFoundError):
         pass
 
@@ -168,8 +185,10 @@ def check_file_references(report: Report):
         # Skip tree diagrams and multi-line code blocks.
         for line in content.split("\n"):
             # Find single-line inline code that looks like a file path
-            refs = re.findall(r'`([^`\n]+\.py[^`]*)`', line)
+            refs = re.findall(r"`([^`\n]+\.py[^`]*)`", line)
-            refs.extend(re.findall(r'`([^`\n]+\\.(csv|json|toml|md|yaml|png|log))`', line))
+            refs.extend(
+                re.findall(r"`([^`\n]+\\.(csv|json|toml|md|yaml|png|log))`", line)
+            )
             for ref in refs:
                 if isinstance(ref, tuple):
                     ref = ref[0]
@@ -183,20 +202,40 @@ def check_file_references(report: Report):
                 if target.exists():
                     continue
                 # Filter out tree-diagram artifacts
-                if any(c in ref for c in ('\u2190', '\u2192', '\u2713', '\u2717',
+                if any(
-                                          '[', ']', '|', '\u2502', '\u2514', '\u251c',
+                    c in ref
-                                          '\u2500', '\u2502', '\u2560', '\u256c')):
+                    for c in (
+                        "\u2190",
+                        "\u2192",
+                        "\u2713",
+                        "\u2717",
+                        "[",
+                        "]",
+                        "|",
+                        "\u2502",
+                        "\u2514",
+                        "\u251c",
+                        "\u2500",
+                        "\u2502",
+                        "\u2560",
+                        "\u256c",
+                    )
+                ):
                     continue
                 # Only warn if it looks like a real file path
-                if re.search(r'[a-zA-Z0-9_\-]+\.[a-zA-Z0-9]+', ref):
+                if re.search(r"[a-zA-Z0-9_\-]+\.[a-zA-Z0-9]+", ref):
                     basename = ref.split("/")[-1]
                     if basename in known_removed or basename in known_placeholders:
                         continue
                     # Skip bare __init__.py (common in tree diagrams, not actionable)
                     if basename == "__init__.py":
                         continue
-                    report.add("WARN", doc_name, "file-reference",
+                    report.add(
-                               f"Referenced file not found: `{ref}`")
+                        "WARN",
+                        doc_name,
+                        "file-reference",
+                        f"Referenced file not found: `{ref}`",
+                    )
 
 
 def check_cli_commands(report: Report):
@@ -207,12 +246,15 @@ def check_cli_commands(report: Report):
     if "bs_pnpi" in agents_md:
         try:
             result = subprocess.run(
-                ["bs_pnpi", "--help"],
+                ["bs_pnpi", "--help"], capture_output=True, text=True, timeout=10
-                capture_output=True, text=True, timeout=10
             )
             if result.returncode != 0:
-                report.add("WARN", "AGENTS.md", "cli",
+                report.add(
-                           f"`bs_pnpi --help` failed: {result.stderr.strip()[:100]}")
+                    "WARN",
+                    "AGENTS.md",
+                    "cli",
+                    f"`bs_pnpi --help` failed: {result.stderr.strip()[:100]}",
+                )
         except (subprocess.TimeoutExpired, FileNotFoundError):
             report.add("WARN", "AGENTS.md", "cli", "bs_pnpi not found in PATH")
 
@@ -220,12 +262,15 @@ def check_cli_commands(report: Report):
     if "bs_exp" in agents_md:
         try:
             result = subprocess.run(
-                ["bs_exp", "--help"],
+                ["bs_exp", "--help"], capture_output=True, text=True, timeout=10
-                capture_output=True, text=True, timeout=10
             )
             if result.returncode != 0:
-                report.add("WARN", "AGENTS.md", "cli",
+                report.add(
-                           f"`bs_exp --help` failed: {result.stderr.strip()[:100]}")
+                    "WARN",
+                    "AGENTS.md",
+                    "cli",
+                    f"`bs_exp --help` failed: {result.stderr.strip()[:100]}",
+                )
         except (subprocess.TimeoutExpired, FileNotFoundError):
             report.add("WARN", "AGENTS.md", "cli", "bs_exp not found in PATH")
 
@@ -234,15 +279,15 @@ def check_imports_in_examples(report: Report):
     """Check that import statements in README examples are valid."""
     readme = read_doc("README.md")
 
-    code_blocks = re.findall(r'```[^\n]*\n(.*?)```', readme, re.DOTALL)
+    code_blocks = re.findall(r"```[^\n]*\n(.*?)```", readme, re.DOTALL)
     for block in code_blocks:
         for line in block.strip().split("\n"):
             line = line.strip()
             if not line.startswith("from ") and not line.startswith("import "):
                 continue
-            match = re.match(r'from\s+(\S+)\s+import', line)
+            match = re.match(r"from\s+(\S+)\s+import", line)
             if not match:
-                match = re.match(r'import\s+(\S+)', line)
+                match = re.match(r"import\s+(\S+)", line)
             if not match:
                 continue
 
@@ -250,8 +295,12 @@ def check_imports_in_examples(report: Report):
             try:
                 __import__(module)
             except ImportError:
-                report.add("WARN", "README.md", "imports",
+                report.add(
-                           f"Cannot import module in example: `{module}`")
+                    "WARN",
+                    "README.md",
+                    "imports",
+                    f"Cannot import module in example: `{module}`",
+                )
 
 
 def check_directory_structure(report: Report):
@@ -268,12 +317,14 @@ def check_directory_structure(report: Report):
 def _check_tree_in_doc(content: str, doc_name: str, report: Report):
     """Extract file references from a markdown tree diagram and check existence."""
     # Find fenced code blocks that look like directory trees
-    trees = re.findall(r'```\w*\n(.*?)```', content, re.DOTALL)
+    trees = re.findall(r"```\w*\n(.*?)```", content, re.DOTALL)
     for tree in trees:
         lines = tree.split("\n")
         for i, line in enumerate(lines):
             # Match lines like: `├── filename.py` or `│   ├── filename.py`
-            match = re.search(r'[\u251c\u2514\u2502\s]*[\u2500\u2501]+\s+([a-zA-Z0-9_\-]+\.\w+)', line)
+            match = re.search(
+                r"[\u251c\u2514\u2502\s]*[\u2500\u2501]+\s+([a-zA-Z0-9_\-]+\.\w+)", line
+            )
             if match:
                 filename = match.group(1)
                 # Determine depth by counting leading tree chars
@@ -288,20 +339,27 @@ def _check_tree_in_doc(content: str, doc_name: str, report: Report):
                 seen_dir = False
                 for j in range(i - 1, max(i - 10, -1), -1):
                     bl = lines[j]
-                    dir_match = re.search(r'[\u251c\u2514\u2502\s]*[\u2500\u2501]+\s+([a-zA-Z0-9_\-]+)/', bl)
+                    dir_match = re.search(
+                        r"[\u251c\u2514\u2502\s]*[\u2500\u2501]+\s+([a-zA-Z0-9_\-]+)/",
+                        bl,
+                    )
                     if dir_match:
                         dir_depth = len(bl) - len(bl.lstrip())
                         if dir_depth < depth:
                             dirs.append(dir_match.group(1))
                             seen_dir = True
-                    elif re.search(r'\w', bl):  # non-empty, non-matching line
+                    elif re.search(r"\w", bl):  # non-empty, non-matching line
                         if seen_dir:
                             break  # stop looking after first non-matching content line
                 if dirs and len(dirs) <= 3:  # cap at 3 levels
                     target = ROOT / "/".join(reversed(dirs)) / filename
                     if not target.exists():
-                        report.add("WARN", doc_name, "structure",
+                        report.add(
-                                   f"File in structure diagram not found: `{'/'.join(reversed(dirs))}/{filename}`")
+                            "WARN",
+                            doc_name,
+                            "structure",
+                            f"File in structure diagram not found: `{'/'.join(reversed(dirs))}/{filename}`",
+                        )
 
 
 def check_cli_args_consistency(report: Report):
@@ -311,30 +369,44 @@ def check_cli_args_consistency(report: Report):
 
     try:
         result = subprocess.run(
-            ["bs_pnpi", "--help"],
+            ["bs_pnpi", "--help"], capture_output=True, text=True, timeout=10
-            capture_output=True, text=True, timeout=10
         )
         if result.returncode == 0:
             actual_flags = set()
             for line in result.stdout.split("\n"):
-                flag_match = re.match(r'\s{0,2}(-\S+)', line)
+                flag_match = re.match(r"\s{0,2}(-\S+)", line)
                 if flag_match:
                     actual_flags.add(flag_match.group(1))
 
-            known_flags = {"-v", "-vv", "-q", "--nuclide", "--output",
+            known_flags = {
-                           "--input", "--dry-run", "--version", "--plot",
+                "-v",
-                           "--log-file", "--intensity-cutoff", "--help",
+                "-vv",
-                           "-h"}
+                "-q",
+                "--nuclide",
+                "--output",
+                "--input",
+                "--dry-run",
+                "--version",
+                "--plot",
+                "--log-file",
+                "--intensity-cutoff",
+                "--help",
+                "-h",
+            }
             mentioned = set()
             # Only match actual CLI flag patterns (--flag-name, not random words)
-            for flag in re.findall(r'--[a-z][a-z0-9-]{2,}', agents_md):
+            for flag in re.findall(r"--[a-z][a-z0-9-]{2,}", agents_md):
                 mentioned.add(flag)
-            for flag in re.findall(r'-[a-z][a-z0-9-]{2,}', readme):
+            for flag in re.findall(r"-[a-z][a-z0-9-]{2,}", readme):
                 mentioned.add(flag)
             unknown = mentioned - known_flags
             for flag in sorted(unknown):
-                report.add("INFO", "AGENTS.md", "cli-args",
+                report.add(
-                           f"Flag `{flag}` mentioned but not in --help (may be custom)")
+                    "INFO",
+                    "AGENTS.md",
+                    "cli-args",
+                    f"Flag `{flag}` mentioned but not in --help (may be custom)",
+                )
     except (subprocess.TimeoutExpired, FileNotFoundError):
         pass
 
@@ -350,8 +422,9 @@ def check_markdown_formatting(report: Report):
         content = path.read_text()
         for i, line in enumerate(content.split("\n"), 1):
             if line != line.rstrip():
-                report.add("INFO", doc_name, f"line {i}",
+                report.add(
-                           "Trailing whitespace detected")
+                    "INFO", doc_name, f"line {i}", "Trailing whitespace detected"
+                )
                 break  # one per file is enough
 
 
@@ -361,18 +434,24 @@ def check_todo_completions(report: Report):
 
     # Find completed items that claim specific files/methods exist
     # Pattern: "- [x] ... implemented: `SomeClass` or `method_name`"
-    completed = re.findall(r'- \[x\].*?(?=- \[|$)', todo, re.DOTALL)
+    completed = re.findall(r"- \[x\].*?(?=- \[|$)", todo, re.DOTALL)
     for block in completed:
         # Skip historical references (items about cleanup, moves, removals)
-        if re.search(r'(?:remove|moved|replaced|deleted|clean up|cleanup)', block, re.IGNORECASE):
+        if re.search(
+            r"(?:remove|moved|replaced|deleted|clean up|cleanup)", block, re.IGNORECASE
+        ):
             continue
         # Look for specific file claims
-        file_claims = re.findall(r'`([^`]+\.py)`', block)
+        file_claims = re.findall(r"`([^`]+\.py)`", block)
         for fc in file_claims:
             target = ROOT / fc
             if not target.exists():
-                report.add("WARN", "TODO.md", "completions",
+                report.add(
-                           f"Completed item references non-existent file: `{fc}`")
+                    "WARN",
+                    "TODO.md",
+                    "completions",
+                    f"Completed item references non-existent file: `{fc}`",
+                )
 
 
 # ---------------------------------------------------------------------------
@@ -395,12 +474,10 @@ CHECKS = [
 def main():
     parser = argparse.ArgumentParser(description="Check documentation consistency")
     parser.add_argument(
-        "--strict", action="store_true",
+        "--strict", action="store_true", help="Treat warnings as errors (exit 1)"
-        help="Treat warnings as errors (exit 1)"
     )
     parser.add_argument(
-        "--json", action="store_true", dest="as_json",
+        "--json", action="store_true", dest="as_json", help="Output findings as JSON"
-        help="Output findings as JSON"
     )
     args = parser.parse_args()
 
@@ -414,15 +491,22 @@ def main():
     # Output
     if args.as_json:
         import json as _json
+
         output = [
-            {"severity": f.severity, "source": f.source,
+            {
-             "section": f.section, "message": f.message}
+                "severity": f.severity,
+                "source": f.source,
+                "section": f.section,
+                "message": f.message,
+            }
             for f in report.findings
         ]
         print(_json.dumps(output, indent=2))
     else:
-        print(f"docs_check: {len(report.findings)} findings "
+        print(
-              f"({len(report.errors)} errors, {len(report.warnings)} warnings)")
+            f"docs_check: {len(report.findings)} findings "
+            f"({len(report.errors)} errors, {len(report.warnings)} warnings)"
+        )
         print(report.summary())
 
     # Exit

scripts/notebook_plots.py

@@ -10,7 +10,6 @@ Each plot gets a descriptive filename based on notebook name and cell index.
 """
 
 import json
-import os
 import sys
 from pathlib import Path
 

scripts/run_notebooks.py

@@ -14,7 +14,6 @@ Usage:
 """
 
 import json
-import os
 import sys
 import base64
 from pathlib import Path

tests/common/test_api_tests.py

@@ -36,54 +36,49 @@ import pytest
 @pytest.mark.api
 def _test_component_is_callable(component, component_name="Component"):
     """Component must be callable with array input."""
-    assert callable(component), (
+    assert callable(component), f"{component_name}: component is not callable"
-        f"{component_name}: component is not callable"
-    )
 
     W = np.array([1.5, 2.0, 3.0])
     result = component(W)
 
     assert isinstance(result, np.ndarray), (
-        f"{component_name}: __call__ returned {type(result)}, "
+        f"{component_name}: __call__ returned {type(result)}, " f"expected np.ndarray"
-        f"expected np.ndarray"
-    )
-    assert result.shape == W.shape, (
-        f"{component_name}: shape mismatch {W.shape} → {result.shape}"
     )
+    assert (
+        result.shape == W.shape
+    ), f"{component_name}: shape mismatch {W.shape} → {result.shape}"
 
 
 @pytest.mark.api
 def _test_component_repr(component, component_name="Component"):
     """Component must have a non-empty repr."""
     repr_str = repr(component)
-    assert isinstance(repr_str, str), (
+    assert isinstance(
-        f"{component_name}: repr returned {type(repr_str)}"
+        repr_str, str
-    )
+    ), f"{component_name}: repr returned {type(repr_str)}"
-    assert len(repr_str) > 0, (
+    assert len(repr_str) > 0, f"{component_name}: repr is empty string"
-        f"{component_name}: repr is empty string"
-    )
     # repr should contain the class name
-    assert component_name in repr_str or component.__class__.__name__ in repr_str, (
+    assert (
-        f"{component_name}: repr should contain class name. Got: {repr_str}"
+        component_name in repr_str or component.__class__.__name__ in repr_str
-    )
+    ), f"{component_name}: repr should contain class name. Got: {repr_str}"
 
 
 @pytest.mark.api
 def _test_component_list_input(component, component_name="Component"):
     """Component must handle Python list input (numpy converts it)."""
     result = component([1.5, 2.0, 3.0])
-    assert isinstance(result, np.ndarray), (
+    assert isinstance(
-        f"{component_name}: list input returned {type(result)}"
+        result, np.ndarray
-    )
+    ), f"{component_name}: list input returned {type(result)}"
 
 
 @pytest.mark.api
 def _test_component_empty_input(component, component_name="Component"):
     """Component must handle empty array input gracefully."""
     result = component(np.array([]))
-    assert isinstance(result, np.ndarray), (
+    assert isinstance(
-        f"{component_name}: empty input returned {type(result)}"
+        result, np.ndarray
-    )
+    ), f"{component_name}: empty input returned {type(result)}"
-    assert result.shape == (0,), (
+    assert result.shape == (
-        f"{component_name}: empty input should return empty array"
+        0,
-    )
+    ), f"{component_name}: empty input should return empty array"

tests/common/test_hypothesis_tests.py

@@ -10,20 +10,18 @@ seconds to complete. They are intended for CI/full test runs, not for
 fast feedback during development.
 """
 
-from typing import List
 
 import numpy as np
-import pytest
 from hypothesis import given, settings, strategies as st
 
 from beta_spectrum.components.fermi import FermiFunction
 from beta_spectrum.components.phase_space import PhaseSpace
 
-
 # ---------------------------------------------------------------------------
 # Fermi function: random Z, A, W combinations
 # ---------------------------------------------------------------------------
 
+
 @given(
     Z=st.integers(min_value=1, max_value=92),
     A=st.integers(min_value=1, max_value=300),
@@ -56,8 +54,7 @@ def test_fermi_monotonic_for_fixed_Z(Z: int):
 
     diffs = np.diff(result)
     assert np.all(diffs <= 0), (
-        f"Fermi function not monotonically decreasing for Z={Z}: "
+        f"Fermi function not monotonically decreasing for Z={Z}: " f"diffs = {diffs}"
-        f"diffs = {diffs}"
     )
 
 
@@ -65,6 +62,7 @@ def test_fermi_monotonic_for_fixed_Z(Z: int):
 # Phase space: random W0, W combinations
 # ---------------------------------------------------------------------------
 
+
 @given(
     W0=st.floats(min_value=2.0, max_value=10.0, allow_infinity=False, allow_nan=False),
     W=st.floats(min_value=1.01, max_value=5.0, allow_infinity=False, allow_nan=False),
@@ -91,7 +89,9 @@ def test_phase_space_threshold_at_W1(W0: float):
     ps = PhaseSpace(W0=W0)
     result = ps(np.array([1.0]))
 
-    assert result[0] == 0.0, f"Phase space should be 0 at W=1 for W0={W0:.2f}, got {result[0]}"
+    assert (
+        result[0] == 0.0
+    ), f"Phase space should be 0 at W=1 for W0={W0:.2f}, got {result[0]}"
 
 
 @given(
@@ -103,4 +103,6 @@ def test_phase_space_endpoint_at_W0(W0: float):
     ps = PhaseSpace(W0=W0)
     result = ps(np.array([W0]))
 
-    assert result[0] == 0.0, f"Phase space should be 0 at W=W0={W0:.2f}, got {result[0]}"
+    assert (
+        result[0] == 0.0
+    ), f"Phase space should be 0 at W=W0={W0:.2f}, got {result[0]}"

tests/common/test_property_tests.py

@@ -52,11 +52,11 @@ or only quality tests (`pytest -m quality`) for fast feedback during development
 import numpy as np
 import pytest
 
-
 # ---------------------------------------------------------------------------
 # Property tests: positivity
 # ---------------------------------------------------------------------------
 
+
 @pytest.mark.property
 def _test_positive_values(component, W, component_name="Component"):
     """Component must return positive values at all W in the physical range.
@@ -82,9 +82,9 @@ def _test_positive_values(component, W, component_name="Component"):
         f"W range: [{W_arr.min():.3f}, {W_arr.max():.3f}], "
         f"result range: [{np.nanmin(result):.6f}, {np.nanmax(result):.6f}]"
     )
-    assert not np.any(np.isinf(result)), (
+    assert not np.any(
-        f"{component_name}: Inf values found in output."
+        np.isinf(result)
-    )
+    ), f"{component_name}: Inf values found in output."
     assert np.all(result > 0), (
         f"{component_name}: non-positive values found. "
         f"Min = {np.min(result):.10f} at W = {W_arr[np.argmin(result)][0]:.4f}"
@@ -92,7 +92,9 @@ def _test_positive_values(component, W, component_name="Component"):
 
 
 @pytest.mark.property
-def _test_non_negative_values(component, W, component_name="Component", allow_zero=True):
+def _test_non_negative_values(
+    component, W, component_name="Component", allow_zero=True
+):
     """Component must return non-negative values (allows zero at physical boundaries).
 
     Use this for components that can legitimately be zero (e.g., phase_space
@@ -106,17 +108,16 @@ def _test_non_negative_values(component, W, component_name="Component", allow_ze
     W_arr = np.asarray(W, dtype=float)
     result = component(W_arr)
 
-    assert not np.any(np.isnan(result)), (
+    assert not np.any(
-        f"{component_name}: NaN values found in output."
+        np.isnan(result)
-    )
+    ), f"{component_name}: NaN values found in output."
-    assert not np.any(np.isinf(result)), (
+    assert not np.any(
-        f"{component_name}: Inf values found in output."
+        np.isinf(result)
-    )
+    ), f"{component_name}: Inf values found in output."
 
     if allow_zero:
         assert np.all(result >= 0), (
-            f"{component_name}: negative values found. "
+            f"{component_name}: negative values found. " f"Min = {np.min(result):.10f}"
-            f"Min = {np.min(result):.10f}"
         )
     else:
         assert np.all(result > 0), (
@@ -129,15 +130,16 @@ def _test_non_negative_values(component, W, component_name="Component", allow_ze
 # Property tests: shape preservation
 # ---------------------------------------------------------------------------
 
+
 @pytest.mark.quality
 def _test_output_shape_preserved(component, W, component_name="Component"):
     """Output shape must match input shape — no flattening or reshaping."""
     W_arr = np.asarray(W, dtype=float)
     result = component(W_arr)
 
-    assert isinstance(result, np.ndarray), (
+    assert isinstance(
-        f"{component_name}: output is {type(result)}, expected np.ndarray"
+        result, np.ndarray
-    )
+    ), f"{component_name}: output is {type(result)}, expected np.ndarray"
     assert result.shape == W_arr.shape, (
         f"{component_name}: shape mismatch. "
         f"Input {W_arr.shape} → Output {result.shape}"
@@ -152,15 +154,14 @@ def _test_scalar_input_returns_array(component, W_scalar, component_name="Compon
         f"{component_name}: single-element input returned {type(result)}, "
         f"expected np.ndarray"
     )
-    assert result.ndim == 1, (
+    assert result.ndim == 1, f"{component_name}: expected 1D output, got {result.ndim}D"
-        f"{component_name}: expected 1D output, got {result.ndim}D"
-    )
 
 
 # ---------------------------------------------------------------------------
 # Property tests: numerical stability
 # ---------------------------------------------------------------------------
 
+
 @pytest.mark.quality
 def _test_no_nan_across_range(component, W, component_name="Component"):
     """No NaN values across the entire energy range."""
@@ -208,6 +209,7 @@ def _test_full_range_stability(component, W, component_name="Component"):
 # Property tests: type correctness
 # ---------------------------------------------------------------------------
 
+
 @pytest.mark.quality
 def _test_output_is_ndarray(component, W, component_name="Component"):
     """Output must be numpy.ndarray for any valid input."""
@@ -224,6 +226,7 @@ def _test_output_is_ndarray(component, W, component_name="Component"):
 # Parametrized test templates for quick component integration
 # ---------------------------------------------------------------------------
 
+
 def make_positive_test(component_class, test_params, component_name=None):
     """Factory function to create a parametrized positivity test.
 
@@ -258,7 +261,7 @@ def make_positive_test(component_class, test_params, component_name=None):
     @pytest.mark.parametrize("W", W_values)
     def test_positive(component_params, W_arr):
         comp = component_class(**component_params)
-        test_positive_values(comp, W_arr, component_name)
+        _test_positive_values(comp, W_arr, component_name)
 
     return test_positive
 
@@ -278,6 +281,6 @@ def make_stability_test(component_class, test_params, component_name=None):
     @pytest.mark.parametrize("W", W_values)
     def test_stability(component_params, W_arr):
         comp = component_class(**component_params)
-        test_full_range_stability(comp, W_arr, component_name)
+        _test_full_range_stability(comp, W_arr, component_name)
 
     return test_stability

tests/integration/test_spectrum_pipeline.py

@@ -178,6 +178,7 @@ class TestDeclarativeDetectorResponse:
 
         detector = BetaSpectrum.create_detector_from_config(config)
 
+        from beta_spectrum.components.detector_response import DetectorResponse
         assert isinstance(detector, DetectorResponse)
         assert detector.n_channels == 512
         assert detector._mode == "analytical"

tests/physics/test_detector_response.py

@@ -13,7 +13,9 @@ except ImportError:
     DetectorResponse = None  # type: ignore[misc, assignment]
 
 
-@pytest.mark.skipif(DetectorResponse is None, reason="DetectorResponse not yet implemented")
+@pytest.mark.skipif(
+    DetectorResponse is None, reason="DetectorResponse not yet implemented"
+)
 class TestAnalyticalGaussianResponse:
     """Test pure Gaussian detector response."""
 

tests/physics/test_exchange.py

@@ -22,7 +22,9 @@ class TestExchangePhysics:
         ex = ExchangeCorrection(Z=80)
         low_W = np.array([1.1])
         result = ex(low_W)
-        assert result[0] > 1.0, f"Exchange must enhance spectrum at low energy for heavy Z: {result[0]}"
+        assert (
+            result[0] > 1.0
+        ), f"Exchange must enhance spectrum at low energy for heavy Z: {result[0]}"
 
     @pytest.mark.physics
     def test_grows_as_energy_decreases(self):
@@ -35,7 +37,9 @@ class TestExchangePhysics:
         s_low = ex(low_W)[0]
         s_lower = ex(lower_W)[0]
 
-        assert s_lower > s_low, f"Exchange must increase at lower energy: {s_low} → {s_lower}"
+        assert (
+            s_lower > s_low
+        ), f"Exchange must increase at lower energy: {s_low} → {s_lower}"
 
     @pytest.mark.physics
     def test_vanishes_at_high_energy(self):
@@ -43,7 +47,9 @@ class TestExchangePhysics:
         ex = ExchangeCorrection(Z=40)
         high_W = np.array([3.0, 5.0])
         result = ex(high_W)
-        assert abs(result[0] - 1.0) < 0.5, f"Exchange must approach unity at high energy: {result}"
+        assert (
+            abs(result[0] - 1.0) < 0.5
+        ), f"Exchange must approach unity at high energy: {result}"
 
 
 class TestExchangeErrorHandling:

tests/physics/test_multi_branch.py

@@ -660,9 +660,9 @@ class TestMultiBranchEdgeCases:
         W, _ = spectrum.get_energy_grid(config)
 
         values = spectrum(W)
-        assert np.all(np.isfinite(values)), (
+        assert np.all(
-            "High-Z multi-branch must not produce NaN/inf"
+            np.isfinite(values)
-        )
+        ), "High-Z multi-branch must not produce NaN/inf"
 
     def test_no_branches_defaults_to_single(self):
         """No branches list should default to single-branch mode."""
@@ -727,9 +727,9 @@ class TestMultiBranchEdgeCases:
             contrib = universal_product * branch.intensity * bs[i]
 
             # Branch contribution should not exceed total
-            assert np.all(contrib <= total + 1e-10), (
+            assert np.all(
-                f"Branch {i} contribution exceeds total at some points"
+                contrib <= total + 1e-10
-            )
+            ), f"Branch {i} contribution exceeds total at some points"
 
             # Branch contribution should be non-negative
             assert np.all(contrib >= 0), f"Branch {i} contribution has negative values"
@@ -779,6 +779,6 @@ class TestMultiBranchEdgeCases:
             assert integral > 0, f"Branch {i} has zero integral"
 
         # Sum of branch integrals should equal total
-        assert np.isclose(sum(integrals), total_integral, rtol=1e-6), (
+        assert np.isclose(
-            "Sum of branch integrals should equal total integral"
+            sum(integrals), total_integral, rtol=1e-6
-        )
+        ), "Sum of branch integrals should equal total integral"

tests/physics/test_neutrino_mass_effects.py

@@ -20,12 +20,12 @@ class TestNeutrinoMassPhaseSpaceEffects:
         result = ps(W_test)
 
         # Should not produce NaN values
-        assert not np.any(np.isnan(result)), (
+        assert not np.any(
-            "Phase space with m_nu=0 should not produce NaN values"
+            np.isnan(result)
-        )
+        ), "Phase space with m_nu=0 should not produce NaN values"
-        assert np.all(result > 0), (
+        assert np.all(
-            "Phase space with m_nu=0 should be positive in physical range"
+            result > 0
-        )
+        ), "Phase space with m_nu=0 should be positive in physical range"
 
     def test_phase_space_with_nonzero_neutrino_mass(self):
         """Test that phase space calculation works with non-zero neutrino mass."""
@@ -34,12 +34,12 @@ class TestNeutrinoMassPhaseSpaceEffects:
         result = ps(W_test)
 
         # Should not produce NaN values for energies above threshold
-        assert not np.any(np.isnan(result)), (
+        assert not np.any(
-            "Phase space with m_nu>0 should not produce NaN values above threshold"
+            np.isnan(result)
-        )
+        ), "Phase space with m_nu>0 should not produce NaN values above threshold"
-        assert np.all(result > 0), (
+        assert np.all(
-            "Phase space with m_nu>0 should be positive above threshold"
+            result > 0
-        )
+        ), "Phase space with m_nu>0 should be positive above threshold"
 
     def test_phase_space_with_neutrino_mass_near_endpoint(self):
         """Test that phase space calculation handles energies near endpoint with neutrino mass."""
@@ -48,18 +48,18 @@ class TestNeutrinoMassPhaseSpaceEffects:
         # Test energies where W0-W > m_nu (should be finite)
         W_above_threshold = np.array([4.8])  # W0-W = 0.2 > m_nu=0.1
         result_above = ps(W_above_threshold)
-        assert not np.any(np.isnan(result_above)), (
+        assert not np.any(
-            "Should produce finite value above threshold"
+            np.isnan(result_above)
-        )
+        ), "Should produce finite value above threshold"
 
         # Test energies where W0-W < m_nu (should be handled properly)
         # With our fix, this should return 0 instead of NaN
         W_below_threshold = np.array([4.95])  # W0-W = 0.05 < m_nu=0.1
         result_below = ps(W_below_threshold)
         # After our fix, NaN values should be replaced with 0
-        assert np.all(result_below == 0.0) or np.all(np.isnan(result_below)), (
+        assert np.all(result_below == 0.0) or np.all(
-            "Should handle below-threshold energies properly (either 0 or NaN)"
+            np.isnan(result_below)
-        )
+        ), "Should handle below-threshold energies properly (either 0 or NaN)"
 
     def test_spectrum_config_with_neutrino_mass(self):
         """Test that SpectrumConfig accepts and stores neutrino mass parameter."""
@@ -72,9 +72,9 @@ class TestNeutrinoMassPhaseSpaceEffects:
             e_step_MeV=0.001,
             neutrino_mass_MeV=0.01,
         )
-        assert config.neutrino_mass_MeV == 0.01, (
+        assert (
-            "SpectrumConfig should store neutrino mass parameter"
+            config.neutrino_mass_MeV == 0.01
-        )
+        ), "SpectrumConfig should store neutrino mass parameter"
 
     def test_beta_spectrum_with_neutrino_mass(self):
         """Test that BetaSpectrum works with neutrino mass in configuration."""
@@ -96,12 +96,12 @@ class TestNeutrinoMassPhaseSpaceEffects:
         result = spectrum(W)
 
         # Should not produce NaN values
-        assert not np.any(np.isnan(result)), (
+        assert not np.any(
-            "BetaSpectrum with neutrino mass should not produce NaN values"
+            np.isnan(result)
-        )
+        ), "BetaSpectrum with neutrino mass should not produce NaN values"
-        assert np.all(result >= 0), (
+        assert np.all(
-            "BetaSpectrum with neutrino mass should be non-negative"
+            result >= 0
-        )
+        ), "BetaSpectrum with neutrino mass should be non-negative"
 
 
 class TestNeutrinoMassCLIIntegration:

tests/physics/test_phase_space.py

@@ -74,9 +74,9 @@ class TestPhaseSpaceNeutrinoMass:
         val_massive = ps_massive(W_near_endpoint)[0]
 
         assert not np.isnan(val_massive), "Should produce finite value"
-        assert val_massive < val_zero, (
+        assert (
-            "Massive neutrino must suppress spectrum near endpoint"
+            val_massive < val_zero
-        )
+        ), "Massive neutrino must suppress spectrum near endpoint"
 
     @pytest.mark.physics
     def test_massive_neutrino_below_threshold(self):

tests/physics/test_radiative.py

@@ -21,7 +21,9 @@ class TestRadiativeEndpointHandling:
         result = rc(W_near_end)
 
         assert not np.isnan(result[0]), "Resummed correction must be finite at endpoint"
-        assert not np.isinf(result[0]), "Resummed correction must not diverge at endpoint"
+        assert not np.isinf(
+            result[0]
+        ), "Resummed correction must not diverge at endpoint"
 
     @pytest.mark.physics
     def test_standard_mode_diverges(self):
@@ -34,7 +36,9 @@ class TestRadiativeEndpointHandling:
         val_far = rc(W_far)[0]
         val_close = rc(W_close)[0]
 
-        assert val_close < val_far, "Standard mode must show divergent behavior near endpoint"
+        assert (
+            val_close < val_far
+        ), "Standard mode must show divergent behavior near endpoint"
 
 
 class TestRadiativeEnergyDependence:
@@ -51,7 +55,9 @@ class TestRadiativeEnergyDependence:
         r_mid = rc(mid_W)[0]
         r_near = rc(near_end_W)[0]
 
-        assert r_near <= r_mid, f"Correction factor should decrease near endpoint: {r_mid} → {r_near}"
+        assert (
+            r_near <= r_mid
+        ), f"Correction factor should decrease near endpoint: {r_mid} → {r_near}"
 
 
 class TestRadiativeResummationSwitch:
@@ -73,8 +79,12 @@ class TestRadiativeResummationSwitch:
         r_standard = rc_standard(W_near)[0]
 
         assert not np.isnan(r_resummed), "Resummed mode must be finite"
-        assert not np.isnan(r_standard), "Standard mode must be finite (mask protects endpoint)"
+        assert not np.isnan(
-        assert r_resummed > r_standard, f"Near endpoint: resummed={r_resummed} > standard={r_standard}"
+            r_standard
+        ), "Standard mode must be finite (mask protects endpoint)"
+        assert (
+            r_resummed > r_standard
+        ), f"Near endpoint: resummed={r_resummed} > standard={r_standard}"
 
     @pytest.mark.physics
     def test_resummation_only_near_endpoint(self):
@@ -87,9 +97,9 @@ class TestRadiativeResummationSwitch:
         r_resummed_far = rc_resummed(W_far)[0]
         r_standard_far = rc_standard(W_far)[0]
 
-        assert np.isclose(r_resummed_far, r_standard_far, rtol=1e-10), (
+        assert np.isclose(
-            f"Far from endpoint: resummed={r_resummed_far}, standard={r_standard_far}"
+            r_resummed_far, r_standard_far, rtol=1e-10
-        )
+        ), f"Far from endpoint: resummed={r_resummed_far}, standard={r_standard_far}"
 
         # Very near endpoint (delta_W < delta_cut): resummed is finite and larger
         W_near = np.array([4.9995])
@@ -121,7 +131,9 @@ class TestRadiativeZDependence:
 
         W_test = np.linspace(1.5, 4.5, 10)
         diff = np.abs(rc_z50(W_test) - rc_z1(W_test))
-        assert np.max(diff) > 1e-4, f"Z=1 and Z=50 should differ: max diff = {np.max(diff)}"
+        assert (
+            np.max(diff) > 1e-4
+        ), f"Z=1 and Z=50 should differ: max diff = {np.max(diff)}"
 
     @pytest.mark.physics
     def test_z_correction_magnitude_reasonable(self):
@@ -129,7 +141,9 @@ class TestRadiativeZDependence:
         rc = RadiativeCorrection(W0=5.0, Z=92, use_endpoint_resummation=True)
         W_test = np.array([3.0])
         result = rc(W_test)
-        assert 0.9 < result[0] < 3.0, f"Z=92 correction should be reasonable: {result[0]}"
+        assert (
+            0.9 < result[0] < 3.0
+        ), f"Z=92 correction should be reasonable: {result[0]}"
 
 
 class TestRadiativeAParameter:
@@ -138,8 +152,12 @@ class TestRadiativeAParameter:
     @pytest.mark.physics
     def test_a_affects_nuclear_model_correction(self):
         """A parameter affects the nuclear-structure-dependent part of O(Z*alpha^2)."""
-        rc_a100 = RadiativeCorrection(W0=5.0, Z=50, A=100, use_endpoint_resummation=True)
+        rc_a100 = RadiativeCorrection(
-        rc_a140 = RadiativeCorrection(W0=5.0, Z=50, A=140, use_endpoint_resummation=True)
+            W0=5.0, Z=50, A=100, use_endpoint_resummation=True
+        )
+        rc_a140 = RadiativeCorrection(
+            W0=5.0, Z=50, A=140, use_endpoint_resummation=True
+        )
 
         W_test = np.array([3.0])
         assert rc_a100(W_test)[0] != rc_a140(W_test)[0], (

tests/quality/test_api_detector_response.py

@@ -13,7 +13,9 @@ except ImportError:
     DetectorResponse = None  # type: ignore[misc, assignment]
 
 
-@pytest.mark.skipif(DetectorResponse is None, reason="DetectorResponse not yet implemented")
+@pytest.mark.skipif(
+    DetectorResponse is None, reason="DetectorResponse not yet implemented"
+)
 class TestFactoryMethods:
     """Test convenience factory methods."""
 
@@ -56,7 +58,9 @@ class TestFactoryMethods:
         assert len(resp.calibration_energies) == 3
 
 
-@pytest.mark.skipif(DetectorResponse is None, reason="DetectorResponse not yet implemented")
+@pytest.mark.skipif(
+    DetectorResponse is None, reason="DetectorResponse not yet implemented"
+)
 class TestEdgeCases:
     """Test edge cases and error handling."""
 

tests/quality/test_api_exchange.py

@@ -18,15 +18,20 @@ class TestExchangeAPI:
         result = ex(np.array([2.0]))
         assert isinstance(result, np.ndarray)
 
+
 class TestExchangeProperties:
     @pytest.mark.property
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             [2.0],
             np.linspace(1.01, 6.0, 50),
-    ])
+        ],
+    )
     def test_positive(self, W):
         ex = ExchangeCorrection(Z=92)
         from tests.common.test_property_tests import _test_positive_values
+
         _test_positive_values(ex, W, component_name="ExchangeCorrection")
 
     @pytest.mark.quality
@@ -35,13 +40,18 @@ class TestExchangeProperties:
         ex = ExchangeCorrection(Z=30)
         W = np.linspace(1.1, 3.0, n)
         from tests.common.test_property_tests import _test_output_shape_preserved
+
         _test_output_shape_preserved(ex, W, component_name="ExchangeCorrection")
 
     @pytest.mark.quality
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             np.linspace(1.01, 6.0, 50),
-    ])
+        ],
+    )
     def test_no_nan(self, W):
         ex = ExchangeCorrection(Z=92)
         from tests.common.test_property_tests import _test_no_nan_across_range
+
         _test_no_nan_across_range(ex, W, component_name="ExchangeCorrection")

tests/quality/test_api_fermi.py

@@ -26,19 +26,24 @@ class TestFermiAPI:
         ff = FermiFunction(Z=20, A=40)
         assert "FermiFunction" in repr(ff)
 
+
 class TestFermiProperties:
     """Shared property tests for FermiFunction."""
 
     @pytest.mark.property
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             [1.5],
             [1.1, 2.0, 3.0],
             np.linspace(1.01, 5.0, 20),
-    ])
+        ],
+    )
     def test_positive(self, W):
         """F₀ must be positive everywhere — it's a probability enhancement factor."""
         ff = FermiFunction(Z=92, A=238)  # Uranium — extreme case
         from tests.common.test_property_tests import _test_positive_values
+
         _test_positive_values(ff, W, component_name="FermiFunction")
 
     @pytest.mark.quality
@@ -48,17 +53,22 @@ class TestFermiProperties:
         ff = FermiFunction(Z=20, A=40)
         W = np.linspace(1.1, 3.0, n)
         from tests.common.test_property_tests import _test_output_shape_preserved
+
         _test_output_shape_preserved(ff, W, component_name="FermiFunction")
 
     @pytest.mark.quality
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             np.linspace(1.01, 6.0, 50),
             np.linspace(1.001, 10.0, 100),
-    ])
+        ],
+    )
     def test_no_nan(self, W):
         """For very heavy nuclei, the loggamma implementation must not overflow."""
         ff = FermiFunction(Z=92, A=238)
         from tests.common.test_property_tests import _test_no_nan_across_range
+
         _test_no_nan_across_range(ff, W, component_name="FermiFunction")
 
     @pytest.mark.quality

tests/quality/test_api_finite_size.py

@@ -23,15 +23,20 @@ class TestFiniteSizeL0API:
         fs = FiniteSizeL0(Z=20, A=40)
         assert "FiniteSizeL0" in repr(fs)
 
+
 class TestFiniteSizeL0Properties:
     @pytest.mark.property
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             [2.0],
             np.linspace(1.05, 6.0, 20),
-    ])
+        ],
+    )
     def test_positive(self, W):
         fs = FiniteSizeL0(Z=92, A=238)
         from tests.common.test_property_tests import _test_positive_values
+
         _test_positive_values(fs, W, component_name="FiniteSizeL0")
 
     @pytest.mark.quality
@@ -40,6 +45,7 @@ class TestFiniteSizeL0Properties:
         fs = FiniteSizeL0(Z=20, A=40)
         W = np.linspace(1.1, 3.0, n)
         from tests.common.test_property_tests import _test_output_shape_preserved
+
         _test_output_shape_preserved(fs, W, component_name="FiniteSizeL0")
 
 
@@ -59,13 +65,17 @@ class TestChargeDistributionUAPI:
 
 class TestChargeDistributionUProperties:
     @pytest.mark.property
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             [2.0],
             np.linspace(1.1, 5.0, 10),
-    ])
+        ],
+    )
     def test_non_negative(self, W):
         u = ChargeDistributionU(Z=20, A=40)
         from tests.common.test_property_tests import _test_non_negative_values
+
         _test_non_negative_values(u, W, component_name="ChargeDistributionU")
 
     @pytest.mark.quality
@@ -74,4 +84,5 @@ class TestChargeDistributionUProperties:
         u = ChargeDistributionU(Z=20, A=40)
         W = np.linspace(1.1, 3.0, n)
         from tests.common.test_property_tests import _test_output_shape_preserved
+
         _test_output_shape_preserved(u, W, component_name="ChargeDistributionU")

tests/quality/test_api_phase_space.py

@@ -21,19 +21,24 @@ class TestPhaseSpaceAPI:
         result = ps(np.array([3.0]))
         assert isinstance(result, np.ndarray)
 
+
 class TestPhaseSpaceProperties:
     """Shared property tests for PhaseSpace."""
 
     @pytest.mark.property
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             [1.5],
             [1.1, 2.0, 3.0],
             np.linspace(1.01, 4.9, 20),
-    ])
+        ],
+    )
     def test_non_negative(self, W):
         """Phase space must be non-negative (zero at boundaries)."""
         ps = PhaseSpace(W0=5.0)
         from tests.common.test_property_tests import _test_non_negative_values
+
         _test_non_negative_values(ps, W, component_name="PhaseSpace")
 
     @pytest.mark.quality
@@ -43,15 +48,20 @@ class TestPhaseSpaceProperties:
         ps = PhaseSpace(W0=5.0)
         W = np.linspace(1.1, 4.9, n)
         from tests.common.test_property_tests import _test_output_shape_preserved
+
         _test_output_shape_preserved(ps, W, component_name="PhaseSpace")
 
     @pytest.mark.quality
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             np.linspace(1.01, 4.99, 50),
             np.linspace(1.001, 4.999, 100),
-    ])
+        ],
+    )
     def test_stability(self, W):
         """Phase space must be stable across the full energy range."""
         ps = PhaseSpace(W0=5.0)
         from tests.common.test_property_tests import _test_full_range_stability
+
         _test_full_range_stability(ps, W, component_name="PhaseSpace")

tests/quality/test_api_radiative.py

@@ -39,13 +39,17 @@ class TestRadiativeAPI:
 
 class TestRadiativeProperties:
     @pytest.mark.property
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             [2.0],
             np.linspace(1.1, 4.9, 20),
-    ])
+        ],
+    )
     def test_positive(self, W):
         rc = RadiativeCorrection(W0=5.0)
         from tests.common.test_property_tests import _test_positive_values
+
         _test_positive_values(rc, W, component_name="RadiativeCorrection")
 
     @pytest.mark.quality
@@ -54,6 +58,7 @@ class TestRadiativeProperties:
         rc = RadiativeCorrection(W0=5.0)
         W = np.linspace(1.1, 4.9, n)
         from tests.common.test_property_tests import _test_output_shape_preserved
+
         _test_output_shape_preserved(rc, W, component_name="RadiativeCorrection")
 
     @pytest.mark.quality
@@ -63,17 +68,22 @@ class TestRadiativeProperties:
         rc = RadiativeCorrection(W0=W0)
         W = np.linspace(1.1, min(9.9, W0 - 0.01), 20)
         from tests.common.test_property_tests import _test_no_nan_across_range
+
         _test_no_nan_across_range(rc, W, component_name=f"RadiativeCorrection(W0={W0})")
 
     @pytest.mark.quality
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             np.linspace(1.0001, 4.9999, 200),
             np.linspace(1.001, 9.99, 100),
-    ])
+        ],
+    )
     def _test_full_range_stability(self, W):
         """Entire energy range from threshold to endpoint must be free of NaN/inf."""
         rc = RadiativeCorrection(W0=5.0, Z=92, use_endpoint_resummation=True)
         from tests.common.test_property_tests import _test_full_range_stability
+
         _test_full_range_stability(rc, W, component_name="RadiativeCorrection(Z=92)")
 
     @pytest.mark.quality

tests/quality/test_api_screening.py

@@ -26,16 +26,21 @@ class TestScreeningAPI:
         sc = ScreeningCorrection(ff)
         assert "Screening" in repr(sc)
 
+
 class TestScreeningProperties:
     @pytest.mark.property
-    @pytest.mark.parametrize("W", [
+    @pytest.mark.parametrize(
+        "W",
+        [
             [2.0],
             np.linspace(1.02, 3.0, 20),
-    ])
+        ],
+    )
     def test_positive(self, W):
         ff = FermiFunction(Z=40, A=95)
         sc = ScreeningCorrection(ff)
         from tests.common.test_property_tests import _test_positive_values
+
         _test_positive_values(sc, W, component_name="ScreeningCorrection")
 
     @pytest.mark.quality
@@ -45,4 +50,5 @@ class TestScreeningProperties:
         sc = ScreeningCorrection(ff)
         W = np.linspace(1.1, 3.0, n)
         from tests.common.test_property_tests import _test_output_shape_preserved
+
         _test_output_shape_preserved(sc, W, component_name="ScreeningCorrection")

tests/quality/test_neutrino_mass_cli.py

@@ -56,9 +56,9 @@ class TestNeutrinoMassPhaseSpace:
         val_massive = ps_massive(W_near_endpoint)[0]
 
         assert not np.isnan(val_massive), "Should produce finite value"
-        assert val_massive < val_zero, (
+        assert (
-            "Massive neutrino must suppress spectrum near endpoint"
+            val_massive < val_zero
-        )
+        ), "Massive neutrino must suppress spectrum near endpoint"
 
 
 class TestCLIArguments: