perf(template-engine): cache script compile verdicts by code hash — unchanged scripts compile once per process

Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj
2026-07-09 16:08:03 -04:00
parent f40f52950e
commit ef59c752ba
3 changed files with 126 additions and 10 deletions
@@ -135,4 +135,35 @@ public class ScriptCompilerTests
        Assert.NotNull(error);
        Assert.Contains("forbidden", error, StringComparison.OrdinalIgnoreCase);
    }
+
+    // --- Compile-verdict cache: unchanged code compiles once per process ---
+
+    [Fact]
+    public void TryCompile_SameCodeTwice_SecondCallIsCacheHit()
+    {
+        ScriptCompileVerdictCache.Clear();
+        var c = new ScriptCompiler();
+        c.TryCompile("return 1;", "A");
+        var hitsBefore = ScriptCompileVerdictCache.Hits;
+        var r = c.TryCompile("return 1;", "B");   // same code, different name
+        Assert.True(r.IsSuccess);
+        Assert.Equal(hitsBefore + 1, ScriptCompileVerdictCache.Hits);
+    }
+
+    [Fact]
+    public void TryCompile_CachedFailure_FormatsNameForEachCaller()
+    {
+        // The stored verdict is name-free; the script name is formatted in at read
+        // time, so two callers of the same bad code get their own name in the message.
+        ScriptCompileVerdictCache.Clear();
+        var c = new ScriptCompiler();
+        var first = c.TryCompile("var x = NoSuchThing.Foo();", "Alpha");
+        var second = c.TryCompile("var x = NoSuchThing.Foo();", "Beta"); // cache hit
+
+        Assert.True(first.IsFailure);
+        Assert.True(second.IsFailure);
+        Assert.Contains("'Alpha'", first.Error);
+        Assert.Contains("'Beta'", second.Error);
+        Assert.Contains("compile", second.Error, StringComparison.OrdinalIgnoreCase);
+    }
 }