expect: Improve report when matcher fails, part 19 (#8367)

* expect: Improve report when matcher fails, part 19

* Delete obsolete code from printConstructorName

* Update CHANGELOG.md

* Call printReceivedConstructorName with constructor arg

* Append extends to be clearer when negative assertion fails

CHANGELOG.md

@@ -10,6 +10,7 @@
 - `[docs]` Add DynamoDB guide ([#8319](https://github.com/facebook/jest/pull/8319))
 - `[expect]` Improve report when matcher fails, part 17 ([#8349](https://github.com/facebook/jest/pull/8349))
 - `[expect]` Improve report when matcher fails, part 18 ([#8356](https://github.com/facebook/jest/pull/8356))
+- `[expect]` Improve report when matcher fails, part 19 ([#8367](https://github.com/facebook/jest/pull/8367))
 
 ### Fixes
 

packages/expect/src/__tests__/__snapshots__/matchers.test.js.snap

@@ -1265,6 +1265,7 @@ exports[`.toBeInstanceOf() failing "a" and [Function String] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: <green>String</>
+
 Received value has no prototype
 Received value: <red>\\"a\\"</>"
 `;
@@ -1274,13 +1275,14 @@ exports[`.toBeInstanceOf() failing /\\w+/ and [Function anonymous] 1`] = `
 
 Expected constructor name is an empty string
 Received constructor: <red>RegExp</>
-Received value: <red>/\\\\w+/</>"
+"
 `;
 
 exports[`.toBeInstanceOf() failing {} and [Function A] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: <green>A</>
+
 Received value has no prototype
 Received value: <red>{}</>"
 `;
@@ -1290,21 +1292,22 @@ exports[`.toBeInstanceOf() failing {} and [Function B] 1`] = `
 
 Expected constructor: <green>B</>
 Received constructor: <red>A</>
-Received value: <red>{}</>"
+"
 `;
 
 exports[`.toBeInstanceOf() failing {} and [Function RegExp] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: <green>RegExp</>
 Received constructor name is an empty string
-Received value: <red>{}</>"
+"
 `;
 
 exports[`.toBeInstanceOf() failing 1 and [Function Number] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: <green>Number</>
+
 Received value has no prototype
 Received value: <red>1</>"
 `;
@@ -1313,6 +1316,7 @@ exports[`.toBeInstanceOf() failing null and [Function String] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: <green>String</>
+
 Received value has no prototype
 Received value: <red>null</>"
 `;
@@ -1321,6 +1325,7 @@ exports[`.toBeInstanceOf() failing true and [Function Boolean] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: <green>Boolean</>
+
 Received value has no prototype
 Received value: <red>true</>"
 `;
@@ -1329,6 +1334,7 @@ exports[`.toBeInstanceOf() failing undefined and [Function String] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: <green>String</>
+
 Received value has no prototype
 Received value: <red>undefined</>"
 `;
@@ -1337,35 +1343,44 @@ exports[`.toBeInstanceOf() passing [] and [Function Array] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: not <green>Array</>
-Received value: <red>[]</>"
+"
 `;
 
 exports[`.toBeInstanceOf() passing {} and [Function A] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: not <green>A</>
-Received value: <red>{}</>"
+"
 `;
 
 exports[`.toBeInstanceOf() passing {} and [Function B] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: not <green>B</>
-Received value: <red>{}</>"
+Received constructor:     <red>C</> extends <green>B</>
+"
+`;
+
+exports[`.toBeInstanceOf() passing {} and [Function B] 2`] = `
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
+
+Expected constructor: not <green>B</>
+Received constructor:     <red>E</> extends … extends <green>B</>
+"
 `;
 
 exports[`.toBeInstanceOf() passing {} and [Function name() {}] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor name is not a string
-Received value: <red>{}</>"
+"
 `;
 
 exports[`.toBeInstanceOf() passing Map {} and [Function Map] 1`] = `
 "<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeInstanceOf<dim>(</><green>expected</><dim>)</>
 
 Expected constructor: not <green>Map</>
-Received value: <red>Map {}</>"
+"
 `;
 
 exports[`.toBeInstanceOf() throws if constructor is not a function 1`] = `

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

@@ -89,16 +89,16 @@ Received message: <red>\\"apple\\"</>
 exports[`toThrow error class did not throw at all 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toThrow<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err\\"</>
+Expected constructor: <green>Err</>
 
 Received function did not throw"
 `;
 
 exports[`toThrow error class threw, but class did not match (error) 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toThrow<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err2\\"</>
-Received name: <red>\\"Error\\"</>
+Expected constructor: <green>Err2</>
+Received constructor: <red>Err</>
 
 Received message: <red>\\"apple\\"</>
 
@@ -108,17 +108,38 @@ Received message: <red>\\"apple\\"</>
 exports[`toThrow error class threw, but class did not match (non-error falsey) 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toThrow<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err2\\"</>
+Expected constructor: <green>Err2</>
 
 Received value: <red>undefined</>
 "
 `;
 
+exports[`toThrow error class threw, but class should not match (error subclass) 1`] = `
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toThrow<dim>(</><green>expected</><dim>)</>
+
+Expected constructor: not <green>Err</>
+Received constructor:     <red>SubErr</> extends <green>Err</>
+
+Received message: <red>\\"apple\\"</>
+
+      <dim>at jestExpect (</>packages/expect/src/__tests__/toThrowMatchers-test.js<dim>:24:74)</>"
+`;
+
+exports[`toThrow error class threw, but class should not match (error subsubclass) 1`] = `
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toThrow<dim>(</><green>expected</><dim>)</>
+
+Expected constructor: not <green>Err</>
+Received constructor:     <red>SubSubErr</> extends … extends <green>Err</>
+
+Received message: <red>\\"apple\\"</>
+
+      <dim>at jestExpect (</>packages/expect/src/__tests__/toThrowMatchers-test.js<dim>:24:74)</>"
+`;
+
 exports[`toThrow error class threw, but class should not match (error) 1`] = `
 "<dim>expect(</><red>received</><dim>).</>not<dim>.</>toThrow<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err\\"</>
-Received name: <red>\\"Error\\"</>
+Expected constructor: not <green>Err</>
 
 Received message: <red>\\"apple\\"</>
 
@@ -174,8 +195,8 @@ Received function did not throw"
 exports[`toThrow promise/async throws if Error-like object is returned threw, but class did not match 1`] = `
 "<dim>expect(</><red>received</><dim>).</>rejects<dim>.</>toThrow<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err2\\"</>
-Received name: <red>\\"Error\\"</>
+Expected constructor: <green>Err2</>
+Received constructor: <red>Err</>
 
 Received message: <red>\\"async apple\\"</>
 
@@ -364,16 +385,16 @@ Received message: <red>\\"apple\\"</>
 exports[`toThrowError error class did not throw at all 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toThrowError<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err\\"</>
+Expected constructor: <green>Err</>
 
 Received function did not throw"
 `;
 
 exports[`toThrowError error class threw, but class did not match (error) 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toThrowError<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err2\\"</>
-Received name: <red>\\"Error\\"</>
+Expected constructor: <green>Err2</>
+Received constructor: <red>Err</>
 
 Received message: <red>\\"apple\\"</>
 
@@ -383,17 +404,38 @@ Received message: <red>\\"apple\\"</>
 exports[`toThrowError error class threw, but class did not match (non-error falsey) 1`] = `
 "<dim>expect(</><red>received</><dim>).</>toThrowError<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err2\\"</>
+Expected constructor: <green>Err2</>
 
 Received value: <red>undefined</>
 "
 `;
 
+exports[`toThrowError error class threw, but class should not match (error subclass) 1`] = `
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toThrowError<dim>(</><green>expected</><dim>)</>
+
+Expected constructor: not <green>Err</>
+Received constructor:     <red>SubErr</> extends <green>Err</>
+
+Received message: <red>\\"apple\\"</>
+
+      <dim>at jestExpect (</>packages/expect/src/__tests__/toThrowMatchers-test.js<dim>:24:74)</>"
+`;
+
+exports[`toThrowError error class threw, but class should not match (error subsubclass) 1`] = `
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toThrowError<dim>(</><green>expected</><dim>)</>
+
+Expected constructor: not <green>Err</>
+Received constructor:     <red>SubSubErr</> extends … extends <green>Err</>
+
+Received message: <red>\\"apple\\"</>
+
+      <dim>at jestExpect (</>packages/expect/src/__tests__/toThrowMatchers-test.js<dim>:24:74)</>"
+`;
+
 exports[`toThrowError error class threw, but class should not match (error) 1`] = `
 "<dim>expect(</><red>received</><dim>).</>not<dim>.</>toThrowError<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err\\"</>
-Received name: <red>\\"Error\\"</>
+Expected constructor: not <green>Err</>
 
 Received message: <red>\\"apple\\"</>
 
@@ -449,8 +491,8 @@ Received function did not throw"
 exports[`toThrowError promise/async throws if Error-like object is returned threw, but class did not match 1`] = `
 "<dim>expect(</><red>received</><dim>).</>rejects<dim>.</>toThrowError<dim>(</><green>expected</><dim>)</>
 
-Expected name: <green>\\"Err2\\"</>
-Received name: <red>\\"Error\\"</>
+Expected constructor: <green>Err2</>
+Received constructor: <red>Err</>
 
 Received message: <red>\\"async apple\\"</>
 

packages/expect/src/__tests__/matchers.test.js

@@ -687,6 +687,8 @@ describe('.toBeInstanceOf()', () => {
   class A {}
   class B {}
   class C extends B {}
+  class D extends C {}
+  class E extends D {}
 
   class HasStaticNameMethod {
     constructor() {}
@@ -705,7 +707,8 @@ describe('.toBeInstanceOf()', () => {
     [new Map(), Map],
     [[], Array],
     [new A(), A],
-    [new C(), B], // subclass
+    [new C(), B], // C extends B
+    [new E(), B], // E extends … extends B
     [new HasStaticNameMethod(), HasStaticNameMethod],
   ].forEach(([a, b]) => {
     test(`passing ${stringify(a)} and ${stringify(b)}`, () => {

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

@@ -146,6 +146,24 @@ class customError extends Error {
     });
 
     describe('error class', () => {
+      class SubErr extends Err {
+        constructor(...args) {
+          super(...args);
+          // In a carefully written error subclass,
+          // name property is equal to constructor name.
+          this.name = this.constructor.name;
+        }
+      }
+
+      class SubSubErr extends SubErr {
+        constructor(...args) {
+          super(...args);
+          // In a carefully written error subclass,
+          // name property is equal to constructor name.
+          this.name = this.constructor.name;
+        }
+      }
+
       it('passes', () => {
         jestExpect(() => {
           throw new Err();
@@ -189,6 +207,22 @@ class customError extends Error {
           }).not[toThrow](Err);
         }).toThrowErrorMatchingSnapshot();
       });
+
+      test('threw, but class should not match (error subclass)', () => {
+        expect(() => {
+          jestExpect(() => {
+            throw new SubErr('apple');
+          }).not[toThrow](Err);
+        }).toThrowErrorMatchingSnapshot();
+      });
+
+      test('threw, but class should not match (error subsubclass)', () => {
+        expect(() => {
+          jestExpect(() => {
+            throw new SubSubErr('apple');
+          }).not[toThrow](Err);
+        }).toThrowErrorMatchingSnapshot();
+      });
     });
 
     describe('error-message', () => {