import { test } from "node:test";
import assert from "node:assert/strict";
import {
  moduleFragment,
  testImportsModule,
  findCoverageDrift,
} from "../../../scripts/check/check-mutation-test-coverage.mjs";

test("moduleFragment returns the 3-segment suffix without extension", () => {
  assert.equal(
    moduleFragment("open-sse/handlers/chatCore/headers.ts"),
    "handlers/chatCore/headers"
  );
  assert.equal(moduleFragment("src/sse/services/auth.ts"), "sse/services/auth");
  // shallow paths just use what is available
  assert.equal(moduleFragment("a/b.ts"), "a/b");
});

test("testImportsModule matches static, dynamic and require imports of the module path", () => {
  const frag = "handlers/chatCore/headers";
  // static import-from
  assert.equal(
    testImportsModule(`import { x } from "@omniroute/open-sse/handlers/chatCore/headers";`, frag),
    true
  );
  // dynamic await import, even split across lines
  assert.equal(
    testImportsModule(`const { y } = await import(\n  "../../open-sse/handlers/chatCore/headers.ts"\n);`, frag),
    true
  );
  // require()
  assert.equal(
    testImportsModule(`const z = require("../../open-sse/handlers/chatCore/headers.ts");`, frag),
    true
  );
  // unrelated module is not matched
  assert.equal(
    testImportsModule(`import { a } from "@omniroute/open-sse/handlers/chatCore/idempotency";`, frag),
    false
  );
  // the fragment appearing only in a comment (not an import string) is NOT a match
  assert.equal(
    testImportsModule(`// see handlers/chatCore/headers for details\nconst a = 1;`, frag),
    false
  );
});

test("findCoverageDrift flags covering unit tests absent from tap.testFiles", () => {
  const mutate = [
    "open-sse/handlers/chatCore/headers.ts",
    "open-sse/handlers/chatCore/idempotency.ts",
    "_a_comment_entry",
  ];
  const tapTestFiles = ["tests/unit/chatcore-headers.test.ts"];
  const unitTests = [
    // covers headers, already in tap -> not drift
    { path: "tests/unit/chatcore-headers.test.ts", content: `await import("../../open-sse/handlers/chatCore/headers.ts");` },
    // covers headers, NOT in tap -> drift
    { path: "tests/unit/no-memory-header.test.ts", content: `const { isNoMemoryRequested } = await import("../../open-sse/handlers/chatCore/headers.ts");` },
    // covers idempotency, NOT in tap -> drift
    { path: "tests/unit/idempo.test.ts", content: `import { x } from "@omniroute/open-sse/handlers/chatCore/idempotency";` },
    // covers nothing mutated -> ignored
    { path: "tests/unit/unrelated.test.ts", content: `import { z } from "@/lib/foo";` },
  ];
  const drift = findCoverageDrift({ mutate, tapTestFiles, unitTests });
  assert.deepEqual(drift["open-sse/handlers/chatCore/headers.ts"], [
    "tests/unit/no-memory-header.test.ts",
  ]);
  assert.deepEqual(drift["open-sse/handlers/chatCore/idempotency.ts"], [
    "tests/unit/idempo.test.ts",
  ]);
  // comment-only mutate entries are skipped
  assert.equal("_a_comment_entry" in drift, false);
});