Reports returned values on received function not throw when expect .toThrow()

e2e/__tests__/toThrowErrorMatchingSnapshot.test.ts

@@ -45,6 +45,24 @@ test("throws the error if tested function didn't throw error", () => {
     writeFiles(TESTS_DIR, {[filename]: template()});
     const {stderr, exitCode} = runJest(DIR, ['-w=1', '--ci=false', filename]);
     expect(stderr).toMatch('Received function did not throw');
+    expect(stderr).toMatch('Returned: undefined');
+    expect(exitCode).toBe(1);
+  }
+});
+
+test("reports stringified returned value if tested function didn't throw error", () => {
+  const filename = 'throws-if-tested-function-did-not-throw.test.js';
+  const template =
+    makeTemplate(`test('throws the error if tested function did not throw error', () => {
+      expect(() => { return { foo: 1, bar: { baz: "2", } };}).toThrowErrorMatchingSnapshot();
+    });
+    `);
+
+  {
+    writeFiles(TESTS_DIR, {[filename]: template()});
+    const {stderr, exitCode} = runJest(DIR, ['-w=1', '--ci=false', filename]);
+    expect(stderr).toMatch('Received function did not throw');
+    expect(stderr).toMatch('Returned: {"bar": {"baz": "2"}, "foo": 1}');
     expect(exitCode).toBe(1);
   }
 });

packages/expect/src/__tests__/__snapshots__/toThrowMatchers.test.ts.snap

@@ -92,6 +92,7 @@ exports[`toThrow error class did not throw at all 1`] = `
 Expected constructor: <g>Err</>
 
 Received function did not throw
+Returned: undefined
 `;
 
 exports[`toThrow error class threw, but class did not match (error) 1`] = `
@@ -230,6 +231,7 @@ exports[`toThrow regexp did not throw at all 1`] = `
 Expected pattern: <g>/apple/</>
 
 Received function did not throw
+Returned: undefined
 `;
 
 exports[`toThrow regexp threw, but message did not match (error) 1`] = `
@@ -271,7 +273,8 @@ exports[`toThrow substring did not throw at all 1`] = `
 
 Expected substring: <g>"apple"</>
 
-Received function did not throw
+Received function did not throw 
+Returned: undefined
 `;
 
 exports[`toThrow substring threw, but message did not match (error) 1`] = `

packages/expect/src/__tests__/toThrowMatchers.test.ts

@@ -50,6 +50,10 @@
       ).toThrowErrorMatchingSnapshot();
     });
 
+    test('did not throw with a promise', async () => {
+      await jestExpect(Promise.resolve('banana')).resolves.not.toThrow('apple')
+    });
+
     test('threw, but message did not match (error)', () => {
       expect(() => {
         jestExpect(() => {
@@ -108,6 +112,10 @@
       ).toThrowErrorMatchingSnapshot();
     });
 
+    test('did not throw at all with a promise', async () => {
+      await jestExpect(Promise.resolve('banana')).resolves.not.toThrow(/apple/)
+    });
+
     test('threw, but message did not match (error)', () => {
       expect(() => {
         jestExpect(() => {
@@ -187,6 +195,10 @@
       ).toThrowErrorMatchingSnapshot();
     });
 
+    test('did not throw at all with a promise', async () => {
+      await jestExpect(Promise.resolve()).resolves.not.toThrow(Err)
+    });
+
     test('threw, but class did not match (error)', () => {
       expect(() => {
         jestExpect(() => {

packages/expect/src/toThrowMatchers.ts

@@ -17,6 +17,7 @@
   printExpected,
   printReceived,
   printWithType,
+  stringify,
 } from 'jest-matcher-utils';
 import {formatStackTrace, separateMessageFromStack} from 'jest-message-util';
 import {
@@ -82,13 +83,14 @@
     };
 
     let thrown = null;
+    let returnedValueOnNotThrow;
 
     if (fromPromise && isError(received)) {
       thrown = getThrown(received);
     } else {
       if (typeof received === 'function') {
         try {
-          received();
+          returnedValueOnNotThrow = received();
         } catch (error) {
           thrown = getThrown(error);
         }
@@ -107,20 +109,61 @@
     }
 
     if (expected === undefined) {
-      return toThrow(matcherName, options, thrown);
+      return toThrow(
+        matcherName,
+        options,
+        thrown,
+        received,
+        returnedValueOnNotThrow,
+      );
     } else if (typeof expected === 'function') {
-      return toThrowExpectedClass(matcherName, options, thrown, expected);
+      return toThrowExpectedClass(
+        matcherName,
+        options,
+        thrown,
+        expected,
+        received,
+        returnedValueOnNotThrow,
+      );
     } else if (typeof expected === 'string') {
-      return toThrowExpectedString(matcherName, options, thrown, expected);
+      return toThrowExpectedString(
+        matcherName,
+        options,
+        thrown,
+        expected,
+        received,
+        returnedValueOnNotThrow,
+      );
     } else if (expected !== null && typeof expected.test === 'function') {
-      return toThrowExpectedRegExp(matcherName, options, thrown, expected);
+      return toThrowExpectedRegExp(
+        matcherName,
+        options,
+        thrown,
+        expected,
+        received,
+        returnedValueOnNotThrow,
+      );
     } else if (
       expected !== null &&
       typeof expected.asymmetricMatch === 'function'
     ) {
-      return toThrowExpectedAsymmetric(matcherName, options, thrown, expected);
+      return toThrowExpectedAsymmetric(
+        matcherName,
+        options,
+        thrown,
+        expected,
+        received,
+        returnedValueOnNotThrow,
+      );
     } else if (expected !== null && typeof expected === 'object') {
-      return toThrowExpectedObject(matcherName, options, thrown, expected);
+      return toThrowExpectedObject(
+        matcherName,
+        options,
+        thrown,
+        expected,
+        received,
+        returnedValueOnNotThrow,
+      );
     } else {
       throw new Error(
         matcherErrorMessage(
@@ -143,6 +186,8 @@
   options: MatcherHintOptions,
   thrown: Thrown | null,
   expected: RegExp,
+  received: unknown,
+  returnedValueOnNotThrow: unknown,
 ): SyncExpectationResult => {
   const pass = thrown !== null && expected.test(thrown.message);
 
@@ -166,7 +211,11 @@
         '\n\n' +
         formatExpected('Expected pattern: ', expected) +
         (thrown === null
-          ? `\n${DID_NOT_THROW}`
+          ? `\n${DID_NOT_THROW}${
+              typeof received === 'function'
+                ? `\nReturned: ${stringify(returnedValueOnNotThrow)}`
+                : ''
+            }`
           : thrown.hasMessage
             ? formatReceived('Received message: ', thrown, 'message') +
               formatStack(thrown)
@@ -184,6 +233,8 @@
   options: MatcherHintOptions,
   thrown: Thrown | null,
   expected: AsymmetricMatcher,
+  received: unknown,
+  returnedValueOnNotThrow: unknown,
 ): SyncExpectationResult => {
   const pass = thrown !== null && expected.asymmetricMatch(thrown.value);
 
@@ -206,7 +257,11 @@
         formatExpected('Expected asymmetric matcher: ', expected) +
         '\n' +
         (thrown === null
-          ? DID_NOT_THROW
+          ? `${DID_NOT_THROW}${
+              typeof received === 'function'
+                ? `\nReturned: ${stringify(returnedValueOnNotThrow)}`
+                : ''
+            }`
           : thrown.hasMessage
             ? formatReceived('Received name:    ', thrown, 'name') +
               formatReceived('Received message: ', thrown, 'message') +
@@ -221,6 +276,8 @@
   options: MatcherHintOptions,
   thrown: Thrown | null,
   expected: Error,
+  received: unknown,
+  returnedValueOnNotThrow: unknown,
 ): SyncExpectationResult => {
   const expectedMessageAndCause = createMessageAndCause(expected);
   const thrownMessageAndCause =
@@ -260,7 +317,11 @@
               expectedMessageAndCause,
             ) +
             '\n' +
-            DID_NOT_THROW
+            `${DID_NOT_THROW}${
+              typeof received === 'function'
+                ? `\nReturned: ${stringify(returnedValueOnNotThrow)}`
+                : ''
+            }`
           : thrown.hasMessage
             ? // eslint-disable-next-line prefer-template
               printDiffOrStringify(
@@ -285,6 +346,8 @@
   options: MatcherHintOptions,
   thrown: Thrown | null,
   expected: Function,
+  received: unknown,
+  returnedValueOnNotThrow: unknown,
 ): SyncExpectationResult => {
   const pass = thrown !== null && thrown.value instanceof expected;
 
@@ -315,7 +378,11 @@
         '\n\n' +
         printExpectedConstructorName('Expected constructor', expected) +
         (thrown === null
-          ? `\n${DID_NOT_THROW}`
+          ? `\n${DID_NOT_THROW}${
+              typeof received === 'function'
+                ? `\nReturned: ${stringify(returnedValueOnNotThrow)}`
+                : ''
+            }`
           : `${
               thrown.value != null &&
               typeof thrown.value.constructor === 'function'
@@ -339,6 +406,8 @@
   options: MatcherHintOptions,
   thrown: Thrown | null,
   expected: string,
+  received: unknown,
+  returnedValueOnNotThrow: unknown,
 ): SyncExpectationResult => {
   const pass = thrown !== null && thrown.message.includes(expected);
 
@@ -362,7 +431,11 @@
         '\n\n' +
         formatExpected('Expected substring: ', expected) +
         (thrown === null
-          ? `\n${DID_NOT_THROW}`
+          ? `\n${DID_NOT_THROW} ${
+              typeof received === 'function'
+                ? `\nReturned: ${stringify(returnedValueOnNotThrow)}`
+                : ''
+            }`
           : thrown.hasMessage
             ? formatReceived('Received message:   ', thrown, 'message') +
               formatStack(thrown)
@@ -375,6 +448,8 @@
   matcherName: string,
   options: MatcherHintOptions,
   thrown: Thrown | null,
+  received: unknown,
+  returnedValueOnNotThrow: unknown,
 ): SyncExpectationResult => {
   const pass = thrown !== null;
 
@@ -392,7 +467,10 @@
         // eslint-disable-next-line prefer-template
         matcherHint(matcherName, undefined, '', options) +
         '\n\n' +
-        DID_NOT_THROW;
+        DID_NOT_THROW +
+        (typeof received === 'function'
+          ? `\nReturned: ${stringify(returnedValueOnNotThrow)}`
+          : '');
 
   return {message, pass};
 };

packages/jest-snapshot/src/__tests__/__snapshots__/printSnapshot.test.ts.snap

@@ -120,6 +120,7 @@ exports[`other error toThrowErrorMatchingSnapshot Received function did not thro
 <d>expect(</><r>received</><d>).</>toThrowErrorMatchingSnapshot<d>()</>
 
 Received function did not throw
+Returned: undefined
 `;
 
 exports[`pass false toMatchInlineSnapshot with properties equals false with snapshot 1`] = `

packages/jest-snapshot/src/index.ts

@@ -509,12 +509,13 @@
   }
 
   let error;
+  let returnedValueOnNotThrow;
 
   if (fromPromise) {
     error = received;
   } else {
     try {
-      received();
+      returnedValueOnNotThrow = received();
     } catch (receivedError) {
       error = receivedError;
     }
@@ -523,7 +524,11 @@
   if (error === undefined) {
     // Because the received value is a function, this is not a matcher error.
     throw new Error(
-      `${matcherHintFromConfig(config, false)}\n\n${DID_NOT_THROW}`,
+      `${matcherHintFromConfig(config, false)}\n\n${DID_NOT_THROW}${
+        typeof received === 'function'
+          ? `\nReturned: ${stringify(returnedValueOnNotThrow)}`
+          : ''
+      }`,
     );
   }