Add support for Error objects in toMatchObject (#4339)

* Add support for Errors in toMatchObject() * Move subsetEqualityMatcher and isObjectWithKeys to the utils directory * Remove files that were created... somehow... * Add types for subsetEquality parameters
jestjs · Aug 24, 2017 · 441bd0a · 441bd0a
1 parent 53c0ccc
commit 441bd0a
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Showing 4 changed files with 46 additions and 16 deletions.
diff --git a/packages/jest-matchers/src/__tests__/__snapshots__/matchers.test.js.snap b/packages/jest-matchers/src/__tests__/__snapshots__/matchers.test.js.snap
@@ -2914,6 +2914,21 @@ Difference:
 <dim> ]"
 `;
 
+exports[`toMatchObject() {pass: false} expect([Error: foo]).toMatchObject([Error: bar]) 1`] = `
+"<dim>expect(<red>received</><dim>).toMatchObject(<green>expected</><dim>)
+
+Expected value to match object:
+  <green>[Error: bar]</>
+Received:
+  <red>[Error: foo]</>
+Difference:
+<green>- Expected</>
+<red>+ Received</>
+
+<green>-[Error: bar]</>
+<red>+[Error: foo]</>"
+`;
+
 exports[`toMatchObject() {pass: false} expect({"a": "a", "c": "d"}).toMatchObject({"a": Any<Number>}) 1`] = `
 "<dim>expect(<red>received</><dim>).toMatchObject(<green>expected</><dim>)
 
@@ -3295,6 +3310,15 @@ Received:
   <red>[1, 2]</>"
 `;
 
+exports[`toMatchObject() {pass: true} expect([Error: foo]).toMatchObject([Error: foo]) 1`] = `
+"<dim>expect(<red>received</><dim>).not.toMatchObject(<green>expected</><dim>)
+
+Expected value not to match object:
+  <green>[Error: foo]</>
+Received:
+  <red>[Error: foo]</>"
+`;
+
 exports[`toMatchObject() {pass: true} expect({"a": "b", "c": "d"}).toMatchObject({"a": "b", "c": "d"}) 1`] = `
 "<dim>expect(<red>received</><dim>).not.toMatchObject(<green>expected</><dim>)
 

diff --git a/packages/jest-matchers/src/__tests__/matchers.test.js b/packages/jest-matchers/src/__tests__/matchers.test.js
@@ -848,6 +848,7 @@ describe('toMatchObject()', () => {
     [[1, 2], [1, 2]],
     [{a: undefined}, {a: undefined}],
     [[], []],
+    [new Error('foo'), new Error('foo')],
   ].forEach(([n1, n2]) => {
     it(`{pass: true} expect(${stringify(n1)}).toMatchObject(${stringify(
       n2,
@@ -883,6 +884,7 @@ describe('toMatchObject()', () => {
     [{}, {a: undefined}],
     [[1, 2, 3], [2, 3, 1]],
     [[1, 2, 3], [1, 2, 2]],
+    [new Error('foo'), new Error('bar')],
   ].forEach(([n1, n2]) => {
     it(`{pass: false} expect(${stringify(n1)}).toMatchObject(${stringify(
       n2,

diff --git a/packages/jest-matchers/src/matchers.js b/packages/jest-matchers/src/matchers.js
@@ -29,6 +29,7 @@ import {
   getPath,
   hasOwnProperty,
   iterableEquality,
+  subsetEquality,
 } from './utils';
 import {equals} from './jasmine_utils';
 
@@ -39,22 +40,6 @@ type ContainIterable =
   | DOMTokenList
   | HTMLCollection<any>;
 
-const isObjectWithKeys = a =>
-  a !== null &&
-  typeof a === 'object' &&
-  !(a instanceof Array) &&
-  !(a instanceof Date);
-const subsetEquality = (object, subset) => {
-  if (!isObjectWithKeys(object) || !isObjectWithKeys(subset)) {
-    return undefined;
-  }
-  return Object.keys(subset).every(
-    key =>
-      hasOwnProperty(object, key) &&
-      equals(object[key], subset[key], [iterableEquality, subsetEquality]),
-  );
-};
-
 const matchers: MatchersObject = {
   toBe(received: any, expected: number) {
     const pass = received === expected;

diff --git a/packages/jest-matchers/src/utils.js b/packages/jest-matchers/src/utils.js
@@ -143,6 +143,25 @@ export const iterableEquality = (a: any, b: any) => {
   return true;
 };
 
+const isObjectWithKeys = a =>
+  a !== null &&
+  typeof a === 'object' &&
+  !(a instanceof Error) &&
+  !(a instanceof Array) &&
+  !(a instanceof Date);
+
+export const subsetEquality = (object: Object, subset: Object) => {
+  if (!isObjectWithKeys(object) || !isObjectWithKeys(subset)) {
+    return undefined;
+  }
+
+  return Object.keys(subset).every(
+    key =>
+      hasOwnProperty(object, key) &&
+      equals(object[key], subset[key], [iterableEquality, subsetEquality]),
+  );
+};
+
 export const partition = <T>(
   items: Array<T>,
   predicate: T => boolean,