Deduplicate TOML rendering and spec test fixtures

src/pdealchemy/notebook_spec.py

@@ -8,6 +8,7 @@
 from pathlib import Path
 
 from pdealchemy.exceptions import ConfigError
+from pdealchemy.toml_rendering import render_toml_string
 
 _CELL_SECTION_MAP: dict[str, tuple[str, ...]] = {
     "instrument": ("instrument",),
@@ -118,20 +119,11 @@ def _looks_like_path(value: str) -> bool:
     return value.startswith(".")
 
 
-def _render_toml_string(value: str) -> str:
-    """Render a TOML string with support for multiline content."""
-    if "\n" in value:
-        escaped = value.replace("'''", "\\'\\'\\'")
-        return f"'''\n{escaped}\n'''"
-    escaped = value.replace("\\", "\\\\").replace('"', '\\"')
-    return f'"{escaped}"'
-
-
 def _render_section(table_path: Iterable[str], values: dict[str, str]) -> list[str]:
     """Render one TOML table section."""
     lines = [f"[{'.'.join(table_path)}]"]
     for key, value in values.items():
-        lines.append(f"{key} = {_render_toml_string(value)}")
+        lines.append(f"{key} = {render_toml_string(value)}")
     lines.append("")
     return lines
 

src/pdealchemy/spec_bridge.py

@@ -8,6 +8,7 @@
 from typing import cast
 
 from pdealchemy.exceptions import ConfigError
+from pdealchemy.toml_rendering import render_toml_string
 
 _BASELINE_SDE_FILE = "library/sde/black_scholes_geometric_brownian_motion.md"
 _BASELINE_PDE_FILE = "library/pde/black_scholes.md"
@@ -39,15 +40,6 @@ class BlackScholesBridgeDefaults:
     monte_carlo_antithetic: bool = True
 
 
-def _render_toml_string(value: str) -> str:
-    """Render a TOML string with support for multiline content."""
-    if "\n" in value:
-        escaped = value.replace("'''", "\\'\\'\\'")
-        return f"'''\n{escaped}\n'''"
-    escaped = value.replace("\\", "\\\\").replace('"', '\\"')
-    return f'"{escaped}"'
-
-
 def _render_toml_float(value: float) -> str:
     """Render a float with stable TOML-friendly formatting."""
     rendered = f"{value:.12g}"
@@ -249,8 +241,8 @@ def spec_to_runtime_toml_content(
         f"# Generated from {spec_toml_path.name} by pdealchemy spec-to-runtime-toml",
         "",
         "[metadata]",
-        f"name = {_render_toml_string(runtime_name)}",
-        f"description = {_render_toml_string(' '.join(runtime_description_parts))}",
+        f"name = {render_toml_string(runtime_name)}",
+        f"description = {render_toml_string(' '.join(runtime_description_parts))}",
         'tags = ["notebook-bridge", "black-scholes", "vanilla"]',
         "",
         "[process]",

src/pdealchemy/toml_rendering.py

@@ -0,0 +1,12 @@
+"""Shared helpers for deterministic TOML value rendering."""
+
+from __future__ import annotations
+
+
+def render_toml_string(value: str) -> str:
+    """Render a TOML string with support for multiline content."""
+    if "\n" in value:
+        escaped = value.replace("'''", "\\'\\'\\'")
+        return f"'''\n{escaped}\n'''"
+    escaped = value.replace("\\", "\\\\").replace('"', '\\"')
+    return f'"{escaped}"'

tests/cli/test_spec_to_runtime_toml.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+from collections.abc import Callable
 from pathlib import Path
 
 from typer.testing import CliRunner
@@ -11,43 +12,12 @@
 runner = CliRunner()
 
 
-def _write_spec_toml(path: Path, *, payoff_file: str = "library/payoff/vanilla_call.md") -> None:
-    path.write_text(
-        "\n".join(
-            [
-                "[metadata]",
-                'name = "Black-Scholes European Call — Specification"',
-                "",
-                "[instrument]",
-                'description = "European vanilla call option in AUD."',
-                'markdown = "European Call"',
-                "",
-                "[mathematics.sde]",
-                'equation_file = "library/sde/black_scholes_geometric_brownian_motion.md"',
-                "",
-                "[mathematics.operator]",
-                'equation_file = "library/pde/black_scholes.md"',
-                "",
-                "[payoff]",
-                f'equation_file = "{payoff_file}"',
-                "",
-                "[numerics]",
-                'markdown_file = "library/discretisation/crank_nicolson_standard.md"',
-                "",
-                "[data.rates]",
-                'equation_file = "library/data/rates_flat.md"',
-                "",
-                "[data.volatility]",
-                'equation_file = "library/data/volatility_constant.md"',
-            ]
-        ),
-        encoding="utf-8",
-    )
-
-
-def test_spec_to_runtime_toml_command_generates_runtime_file(tmp_path: Path) -> None:
+def test_spec_to_runtime_toml_command_generates_runtime_file(
+    tmp_path: Path,
+    write_spec_toml: Callable[..., None],
+) -> None:
     spec_path = tmp_path / "spec.toml"
-    _write_spec_toml(spec_path)
+    write_spec_toml(spec_path)
     runtime_path = tmp_path / "runtime.toml"
 
     result = runner.invoke(
@@ -68,9 +38,12 @@ def test_spec_to_runtime_toml_command_generates_runtime_file(tmp_path: Path) ->
     assert "[numerics]" in rendered
 
 
-def test_spec_to_runtime_toml_command_rejects_unsupported_baseline(tmp_path: Path) -> None:
+def test_spec_to_runtime_toml_command_rejects_unsupported_baseline(
+    tmp_path: Path,
+    write_spec_toml: Callable[..., None],
+) -> None:
     spec_path = tmp_path / "spec.toml"
-    _write_spec_toml(spec_path, payoff_file="library/payoff/custom_payoff.md")
+    write_spec_toml(spec_path, payoff_file="library/payoff/custom_payoff.md")
 
     result = runner.invoke(app, ["spec-to-runtime-toml", str(spec_path)])
 

tests/conftest.py

@@ -0,0 +1,50 @@
+"""Shared pytest fixtures for test inputs and builders."""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from pathlib import Path
+
+import pytest
+
+_DEFAULT_PAYOFF_FILE = "library/payoff/vanilla_call.md"
+
+
+def _write_spec_toml(path: Path, *, payoff_file: str = _DEFAULT_PAYOFF_FILE) -> None:
+    path.write_text(
+        "\n".join(
+            [
+                "[metadata]",
+                'name = "Black-Scholes European Call — Specification"',
+                "",
+                "[instrument]",
+                'description = "European vanilla call option in AUD."',
+                'markdown = "European Call"',
+                "",
+                "[mathematics.sde]",
+                'equation_file = "library/sde/black_scholes_geometric_brownian_motion.md"',
+                "",
+                "[mathematics.operator]",
+                'equation_file = "library/pde/black_scholes.md"',
+                "",
+                "[payoff]",
+                f'equation_file = "{payoff_file}"',
+                "",
+                "[numerics]",
+                'markdown_file = "library/discretisation/crank_nicolson_standard.md"',
+                "",
+                "[data.rates]",
+                'equation_file = "library/data/rates_flat.md"',
+                "",
+                "[data.volatility]",
+                'equation_file = "library/data/volatility_constant.md"',
+            ]
+        ),
+        encoding="utf-8",
+    )
+
+
+@pytest.fixture
+def write_spec_toml() -> Callable[..., None]:
+    """Provide a reusable Black-Scholes specification TOML writer."""
+    return _write_spec_toml

tests/notebook/test_spec_bridge.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+from collections.abc import Callable
 from pathlib import Path
 
 import pytest
@@ -10,43 +11,12 @@
 from pdealchemy.spec_bridge import spec_to_runtime_toml_content, spec_to_runtime_toml_file
 
 
-def _write_spec_toml(path: Path, *, payoff_file: str = "library/payoff/vanilla_call.md") -> None:
-    path.write_text(
-        "\n".join(
-            [
-                "[metadata]",
-                'name = "Black-Scholes European Call — Specification"',
-                "",
-                "[instrument]",
-                'description = "European vanilla call option in AUD."',
-                'markdown = "European Call"',
-                "",
-                "[mathematics.sde]",
-                'equation_file = "library/sde/black_scholes_geometric_brownian_motion.md"',
-                "",
-                "[mathematics.operator]",
-                'equation_file = "library/pde/black_scholes.md"',
-                "",
-                "[payoff]",
-                f'equation_file = "{payoff_file}"',
-                "",
-                "[numerics]",
-                'markdown_file = "library/discretisation/crank_nicolson_standard.md"',
-                "",
-                "[data.rates]",
-                'equation_file = "library/data/rates_flat.md"',
-                "",
-                "[data.volatility]",
-                'equation_file = "library/data/volatility_constant.md"',
-            ]
-        ),
-        encoding="utf-8",
-    )
-
-
-def test_spec_to_runtime_toml_content_renders_runtime_shape(tmp_path: Path) -> None:
+def test_spec_to_runtime_toml_content_renders_runtime_shape(
+    tmp_path: Path,
+    write_spec_toml: Callable[..., None],
+) -> None:
     spec_path = tmp_path / "spec.toml"
-    _write_spec_toml(spec_path)
+    write_spec_toml(spec_path)
 
     rendered = spec_to_runtime_toml_content(spec_path)
 
@@ -58,28 +28,37 @@ def test_spec_to_runtime_toml_content_renders_runtime_shape(tmp_path: Path) -> N
     assert "[numerics.grid]" in rendered
 
 
-def test_spec_to_runtime_toml_file_writes_default_pricing_suffix(tmp_path: Path) -> None:
+def test_spec_to_runtime_toml_file_writes_default_pricing_suffix(
+    tmp_path: Path,
+    write_spec_toml: Callable[..., None],
+) -> None:
     spec_path = tmp_path / "spec_black_scholes.toml"
-    _write_spec_toml(spec_path)
+    write_spec_toml(spec_path)
 
     output_path = spec_to_runtime_toml_file(spec_path, overwrite=True)
     assert output_path == tmp_path / "spec_black_scholes.pricing.toml"
     assert output_path.exists()
 
 
-def test_spec_to_runtime_toml_file_rewrites_blueprint_suffix(tmp_path: Path) -> None:
+def test_spec_to_runtime_toml_file_rewrites_blueprint_suffix(
+    tmp_path: Path,
+    write_spec_toml: Callable[..., None],
+) -> None:
     spec_path = tmp_path / "black_scholes_blueprint.toml"
-    _write_spec_toml(spec_path)
+    write_spec_toml(spec_path)
 
     output_path = spec_to_runtime_toml_file(spec_path, overwrite=True)
 
     assert output_path == tmp_path / "black_scholes_pricing.toml"
     assert output_path.exists()
 
 
-def test_spec_to_runtime_toml_rejects_unsupported_payoff_mapping(tmp_path: Path) -> None:
+def test_spec_to_runtime_toml_rejects_unsupported_payoff_mapping(
+    tmp_path: Path,
+    write_spec_toml: Callable[..., None],
+) -> None:
     spec_path = tmp_path / "spec.toml"
-    _write_spec_toml(spec_path, payoff_file="library/payoff/custom_payoff.md")
+    write_spec_toml(spec_path, payoff_file="library/payoff/custom_payoff.md")
 
     with pytest.raises(ConfigError, match="Unsupported baseline mapping for \\[payoff\\]"):
         _ = spec_to_runtime_toml_content(spec_path)