refactor(javascript): group domain semantics and contracts (#907)

src/domain/javascript/javascriptSemanticAnalysis.function_names.test.ts

@@ -0,0 +1,54 @@
+import { expect, it } from "vitest";
+
+import { analyzeJavaScriptSemantics } from "./javascriptSemanticAnalysis.js";
+
+it.each(["execute", "{execute}", "...execute", "execute = () => 'DEFAULT'"])(
+  "lets %s parameters shadow a named function expression",
+  (parameter) => {
+    const ir = analyzeJavaScriptSemantics(
+      `const task = function execute(${parameter}) { return execute(); };`,
+    );
+    const call = ir.callSites[0];
+    expect(call?.calleeCallableIds).toEqual([]);
+    expect(call?.resolution).toBe("unresolved");
+    const bindings = ir.bindings.filter(({ name }) => name === "execute");
+    expect(bindings).toHaveLength(2);
+    expect(bindings.map(({ kind }) => kind).sort()).toEqual([
+      "function",
+      "parameter",
+    ]);
+  },
+);
+
+it.each(["var", "let", "const"])(
+  "lets body %s declarations shadow a named function expression",
+  (kind) => {
+    const ir = analyzeJavaScriptSemantics(`const task = function execute() {
+    ${kind} execute = () => 'LOCAL';
+    return execute();
+  };`);
+    const local = ir.callables.find(
+      ({ location }) => location.start.line === 2,
+    );
+    expect(ir.callSites[0]?.calleeCallableIds).toEqual([local?.callableId]);
+    expect(ir.callSites[0]?.resolution).toBe("exact");
+  },
+);
+
+it("preserves recursive function-name resolution without leaking the name", () => {
+  const ir = analyzeJavaScriptSemantics(`const task = function execute(depth) {
+    return depth === 0 ? 'DONE' : execute(depth - 1);
+  };
+  execute();`);
+  const own = ir.callables.find(({ name }) => name === "execute");
+  expect(ir.callSites[0]?.calleeCallableIds).toEqual([own?.callableId]);
+  expect(ir.callSites[1]?.calleeCallableIds).toEqual([]);
+});
+
+it("retains an unshadowed function name in parameter defaults", () => {
+  const ir = analyzeJavaScriptSemantics(
+    `const task = function execute(value = execute()) { return value; };`,
+  );
+  const own = ir.callables.find(({ name }) => name === "execute");
+  expect(ir.callSites[0]?.calleeCallableIds).toEqual([own?.callableId]);
+});