feat: Add Python consistency tests for calculator definitions and refactor QuickConversionTable to explicitly pass calculator configuration to its row builder.

hdyc-svelte/src/lib/components/QuickConversionTable.svelte

@@ -8,8 +8,8 @@
 
   type Row = { input: number; output: string };
 
-  const buildRow = (value: number): Row => {
+  const buildRow = (value: number, c: CalculatorDef): Row => {
-    const formatted = solve(config, 1, value.toString(), '', '');
+    const formatted = solve(c, 1, value.toString(), '', '');
     return {
       input: value,
       output: formatted.val2 || '—',
@@ -22,8 +22,8 @@
   let outputLabel = 'target units';
 
   $: supportsTable = ['standard', 'inverse'].includes(config.type);
-  $: rows = supportsTable
+  $: rows = (config && supportsTable)
-    ? numericSamples.map(buildRow)
+    ? numericSamples.map(v => buildRow(v, config))
     : [];
   $: inputLabel = config.labels?.in1 ?? 'source units';
   $: outputLabel = config.labels?.in2 ?? 'target units';

hdyc-svelte/src/routes/[slug]/+page.svelte

@@ -82,7 +82,9 @@
 
 <h1 class="page-title calculator-page-title">{calc.name}</h1>
 
-<Calculator config={calc} showTitle={false} />
+{#key calc.slug}
+  <Calculator config={calc} showTitle={false} />
+{/key}
 
 <div class="seo-content">
   {#if calc.descriptionHTML}

tests/test_consistency.py

@@ -0,0 +1,106 @@
+
+import math
+import re
+import unittest
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+CALCULATORS_TS = ROOT / "hdyc-svelte" / "src" / "lib" / "data" / "calculators.ts"
+
+def _js_fmt(n: float) -> str:
+    """Mimics the fmt() function in engine.ts"""
+    if not math.isfinite(n):
+        return str(n)
+    if n == 0:
+        return "0"
+    if abs(n) < 1e-6:
+        return f"{n:.6e}".replace("e-0", "e-").replace("e+0", "e+")
+    
+    # engine.ts uses parseFloat(n.toFixed(6)).toString()
+    rounded = round(n, 6)
+    if rounded == 0: # Handle -0.0
+        return "0"
+    if rounded == int(rounded):
+        return str(int(rounded))
+    return str(rounded)
+
+def _js_fmt_precise(n: float) -> str:
+    """Mimics formatExampleValue in QuickConversionExample.svelte"""
+    if n is None or math.isnan(n):
+        return "—"
+    if not math.isfinite(n):
+        return str(n)
+    if n == 0:
+        return "0"
+    
+    rounded = round(n, 6)
+    if rounded != 0:
+        if rounded == int(rounded):
+            return str(int(rounded))
+        return str(rounded)
+    
+    # Precise version for very small numbers
+    precise = f"{n:.12f}".rstrip('0').rstrip('.')
+    return precise if precise else "0"
+
+class TestCalculatorsConsistency(unittest.TestCase):
+    def test_standard_calculators_consistency(self):
+        text = CALCULATORS_TS.read_text(encoding="utf-8")
+        
+        # Extract the calculators array content
+        match = re.search(r"export const calculators: CalculatorDef\[\] = \[(.*?)\];", text, re.S)
+        self.assertTrue(match, "Could not find calculators array in calculators.ts")
+        
+        body = match.group(1)
+        # Split by '{"slug":' to avoid splitting on nested braces
+        raw_entries = body.split('{"slug":')
+        
+        errors = []
+        for raw_entry in raw_entries:
+            if not raw_entry.strip():
+                continue
+            entry = '{"slug":' + raw_entry
+            slug_match = re.search(r'"slug": "(.*?)"', entry)
+            if not slug_match:
+                continue
+            slug = slug_match.group(1)
+            
+            type_match = re.search(r'"type": "(.*?)"', entry)
+            if not type_match or type_match.group(1) != "standard":
+                continue
+            
+            # Use non-greedy search for factor/offset and handle potential whitespace
+            factor_match = re.search(r'"factor":\s*([0-9.eE+-]+)', entry)
+            offset_match = re.search(r'"offset":\s*([0-9.eE+-]+)', entry)
+            
+            factor = float(factor_match.group(1)) if factor_match else 1.0
+            offset = float(offset_match.group(1)) if offset_match else 0.0
+            
+            # 1. Formula Hint vs Chart Row 1 Consistency
+            # Logic: solve(config, 1, "1") -> val2 = fmt(1 * factor + offset)
+            row_one_output = _js_fmt(1.0 * factor + offset)
+            
+            # 2. How to convert Examples Consistency (Inverse)
+            if factor != 0:
+                reverse_val = (1.0 - offset) / factor
+                formatted_reverse = _js_fmt_precise(reverse_val)
+                
+                # Specific check for Réaumur to Kelvin (User request)
+                if slug == "reaumur-to-kelvin":
+                    if formatted_reverse != "-217.72":
+                        errors.append(f"[{slug}] Reverse example mismatch: expected -217.72, got {formatted_reverse}")
+                    if row_one_output != "274.4":
+                        errors.append(f"[{slug}] Chart row 1 mismatch: expected 274.4, got {row_one_output}")
+
+                # Specific check for Feet per minute to Knots (Previous bug fix)
+                if slug == "feet-per-minute-to-knots":
+                    if row_one_output != "0.009875":
+                        errors.append(f"[{slug}] Chart row 1 mismatch: expected 0.009875, got {row_one_output}")
+                    if formatted_reverse != "101.268504":
+                        errors.append(f"[{slug}] Reverse example mismatch: expected 101.268504, got {formatted_reverse}")
+
+        if errors:
+            self.fail("\n" + "\n".join(errors))
+
+if __name__ == "__main__":
+    unittest.main()