spyOn should support zero key in objects (fix jestjs#14077)

octaharon · Apr 18, 2023 · a5e5ac0 · a5e5ac0
1 parent 15af9b3
commit a5e5ac0
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Showing 2 changed files with 23 additions and 1 deletion.
diff --git a/packages/jest-mock/src/__tests__/index.test.ts b/packages/jest-mock/src/__tests__/index.test.ts
@@ -1308,6 +1308,15 @@ describe('moduleMocker', () => {
       expect(() => {
         moduleMocker.spyOn(null, 'method');
       }).toThrow('spyOn could not find an object to spy on for method');
+      expect(() => {
+        moduleMocker.spyOn({} as Record<string, any>, '');
+      }).toThrow('No property name supplied');
+      expect(() => {
+        moduleMocker.spyOn({} as Record<number, any>, NaN);
+      }).toThrow('No property name supplied');
+      expect(() => {
+        moduleMocker.spyOn({}, undefined);
+      }).toThrow('No property name supplied');
       expect(() => {
         moduleMocker.spyOn({}, 'method');
       }).toThrow(
@@ -1320,6 +1329,19 @@ describe('moduleMocker', () => {
       );
     });
 
+    it('should not throw when spying on a method named `0`', () => {
+      let haveBeenCalled = false;
+      const obj = {
+        0: () => {
+          haveBeenCalled = true;
+        },
+      };
+      const spy = moduleMocker.spyOn(obj, 0);
+      obj[0].call(null);
+      expect(haveBeenCalled).toBe(true);
+      expect(spy).toHaveBeenCalled();
+    });
+
     it('supports clearing a spy', () => {
       let methodOneCalls = 0;
       const obj = {

diff --git a/packages/jest-mock/src/index.ts b/packages/jest-mock/src/index.ts
@@ -1168,7 +1168,7 @@ export class ModuleMocker {
       );
     }
 
-    if (!methodKey) {
+    if (!methodKey && !Number.isFinite(methodKey)) {
       throw new Error('No property name supplied');
     }