Function assertSnapshot

testing/snapshot.ts:552–608

(
  context: Deno.TestContext,
  actual: unknown,
  msgOrOpts?: string | SnapshotOptions<unknown>,
)

  message?: string,
): Promise<void>;
export async function assertSnapshot(
  context: Deno.TestContext,
  actual: unknown,
  msgOrOpts?: string | SnapshotOptions<unknown>,
) {
  const options = getOptions(msgOrOpts);
  const assertSnapshotContext = AssertSnapshotContext.fromOptions(
    context,
    options,
  );
  const testName = getTestName(context, options);
  const count = assertSnapshotContext.getCount(testName);
  const name = `${testName} ${count}`;
  const expectedSnapshot = await assertSnapshotContext.getSnapshot(
    name,
    options,
  );

  assertSnapshotContext.pushSnapshotToUpdateQueue(name);
  const serializer = options.serializer ?? serialize;
  const actualSnapshot = serializer(actual);
  if (getIsUpdate(options)) {
    await assertSnapshotContext.registerTeardown();
    if (!equal(actualSnapshot, expectedSnapshot)) {
      assertSnapshotContext.updateSnapshot(name, actualSnapshot);
    }
  } else {
    if (
      !assertSnapshotContext.hasSnapshot(name) ||
      typeof expectedSnapshot === "undefined"
    ) {
      throw new AssertionError(
        getErrorMessage(`Missing snapshot: ${name}`, options),
      );
    }

    if (equal(actualSnapshot, expectedSnapshot)) {
      return;
    }

    throw new AssertionError(
      getSnapshotNotMatchMessage(actualSnapshot, expectedSnapshot, options),
    );
  }

  function getTestName(
    context: Deno.TestContext,
    options?: SnapshotOptions,
  ): string {
    if (options && options.name) {
      return options.name;
    } else if (context.parent) {
      return `${getTestName(context.parent)} > ${context.name}`;
    }
    return context.name;
  }
}