add validation on snapshot name

Author: bakamitai456

e2e/__tests__/toMatchNamedSnapshot.test.ts

@@ -170,6 +170,23 @@ test('mark snapshots as obsolete in skipped tests if snapshot name does not matc
   }
 });
 
+test('throws the error if snapshot name is not string', () => {
+  const filename = 'no-obsolete-if-skipped.test.js';
+  const template = makeTemplate(`
+      test('will be error', () => {
+        expect({a: 6}).toMatchNamedSnapshot(true);
+      });
+      `);
+
+  {
+    writeFiles(TESTS_DIR, {[filename]: template(['test.skip'])});
+    const {stderr, exitCode} = runJest(DIR, ['-w=1', '--ci=false', filename]);
+    console.log(stderr);
+    expect(stderr).toMatch('Expected snapshotName must be a string');
+    expect(exitCode).toBe(1);
+  }
+});
+
 test('accepts custom snapshot name', () => {
   const filename = 'accept-custom-snapshot-name.test.js';
   const template = makeTemplate(`test('accepts custom snapshot name', () => {

e2e/__tests__/toThrowErrorMatchingNamedSnapshot.test.ts

@@ -52,6 +52,22 @@ test("throws the error if tested function didn't throw error", () => {
   }
 });
 
+test('throws the error if snapshot name is not string', () => {
+  const filename = 'throws-if-tested-function-did-not-throw.test.js';
+  const template =
+    makeTemplate(`test('throws the error if snapshot name is not string', () => {
+      expect(() => { throw new Error('apple'); }).toThrowErrorMatchingNamedSnapshot(true);
+    });
+    `);
+
+  {
+    writeFiles(TESTS_DIR, {[filename]: template()});
+    const {stderr, exitCode} = runJest(DIR, ['-w=1', '--ci=false', filename]);
+    expect(stderr).toMatch('Expected snapshotName must be a string');
+    expect(exitCode).toBe(1);
+  }
+});
+
 test('accepts custom snapshot name', () => {
   const filename = 'accept-custom-snapshot-name.test.js';
   const template = makeTemplate(`test('accepts custom snapshot name', () => {

packages/jest-snapshot/src/index.ts

@@ -230,15 +230,31 @@ export const toMatchSnapshot: MatcherFunctionWithContext<
 export const toMatchNamedSnapshot: MatcherFunctionWithContext<
   Context,
   [snapshotName: string, properties?: object]
-> = function (received, snapshotName, properties?) {
+> = function (received: unknown, snapshotName: unknown, properties?: unknown) {
   const matcherName = 'toMatchNamedSnapshot';
 
+  if (typeof snapshotName !== 'string') {
+    const options: MatcherHintOptions = {
+      isNot: this.isNot,
+      promise: this.promise,
+    };
+    const printedWithType = printWithType(
+      'Expected snapshotName',
+      snapshotName,
+      printExpected,
+    );
+
+    throw new Error(
+      matcherErrorMessage(
+        matcherHint(matcherName, undefined, PROPERTIES_ARG, options),
+        `Expected ${EXPECTED_COLOR('snapshotName')} must be a string`,
+        printedWithType,
+      ),
+    );
+  }
+
   if (properties !== undefined) {
-    if (
-      Array.isArray(properties) ||
-      typeof properties !== 'object' ||
-      properties === null
-    ) {
+    if (typeof properties !== 'object' || properties === null) {
       const options: MatcherHintOptions = {
         isNot: this.isNot,
         promise: this.promise,
@@ -530,9 +546,29 @@ export const toThrowErrorMatchingInlineSnapshot: MatcherFunctionWithContext<
 export const toThrowErrorMatchingNamedSnapshot: MatcherFunctionWithContext<
   Context,
   [snapshotName: string, fromPromise?: boolean]
-> = function (received, snapshotName, fromPromise) {
+> = function (received: unknown, snapshotName: unknown, fromPromise: unknown) {
   const matcherName = 'toThrowErrorMatchingNamedSnapshot';
 
+  if (typeof snapshotName !== 'string') {
+    const options: MatcherHintOptions = {
+      isNot: this.isNot,
+      promise: this.promise,
+    };
+    const printedWithType = printWithType(
+      'Expected snapshotName',
+      snapshotName,
+      printExpected,
+    );
+
+    throw new Error(
+      matcherErrorMessage(
+        matcherHint(matcherName, undefined, PROPERTIES_ARG, options),
+        `Expected ${EXPECTED_COLOR('snapshotName')} must be a string`,
+        printedWithType,
+      ),
+    );
+  }
+
   return _toThrowErrorMatchingSnapshot(
     {
       context: this,