jest-mock - npm Package Compare versions

Comparing version 11.0.0 to 11.0.1

package.json

 {
   "name": "jest-mock",
-  "version": "11.0.0",
+  "version": "11.0.1",
   "repository": {
@@ -5,0 +5,0 @@ "type": "git",

README.md

@@ -93,5 +93,10 @@ # jest-mock
 
+##### `.mockImplementationOnce(function)`
+
+Pushes the given mock implementation onto a FIFO queue of mock
+implementations for the function.
+
 ##### `.mockImplementation(function)`
 
-Sets a mock implementation for the function.
+Sets the default mock implementation for the function.
 
@@ -104,10 +109,11 @@ ##### `.mockReturnThis()`
 
-In case both `mockImplementation()` and
+In case both `mockImplementationOnce()/mockImplementation()` and
 `mockReturnValueOnce()/mockReturnValue()` are called. The priority of which to
 use is based on what is the last call:
 - if the last call is mockReturnValueOnce() or mockReturnValue(),
-  use the specific return specific return value or default return value.
+  use the specific return value or default return value.
   If specific return values are used up or no default return value is set,
   fall back to try mockImplementation();
-- if the last call is mockImplementation(), run the given implementation
-  and return the result.
+- if the last call is mockImplementationOnce() or mockImplementation(),
+  run the specific implementation and return the result or run default
+  implementation and return the result.

src/__tests__/jest-mock-test.js

@@ -126,2 +126,35 @@ /**
   });
+
+  describe('mockImplementationOnce', () => {
+     it('should mock single call to a mock function', () => {
+      const mockFn = moduleMocker.getMockFunction();
+
+      mockFn.mockImplementationOnce(() => {
+        return 'Foo';
+      }).mockImplementationOnce(() => {
+        return 'Bar';
+      });
+
+      expect(mockFn()).toBe('Foo');
+      expect(mockFn()).toBe('Bar');
+      expect(mockFn()).toBeUndefined();
+    });
+
+    it('should fallback to default mock function when no specific mock is available', () => {
+      const mockFn = moduleMocker.getMockFunction();
+
+      mockFn.mockImplementationOnce(() => {
+        return 'Foo';
+      }).mockImplementationOnce(() => {
+        return 'Bar';
+      }).mockImplementation(() => {
+        return 'Default';
+      });
+
+      expect(mockFn()).toBe('Foo');
+      expect(mockFn()).toBe('Bar');
+      expect(mockFn()).toBe('Default');
+      expect(mockFn()).toBe('Default');
+    });
+  });
 });

src/index.js

@@ -192,2 +192,3 @@ /**
     const specificReturnValues = [];
+    const specificMockImpls = [];
     const calls = [];
@@ -224,3 +225,3 @@ const instances = [];
       // mockReturnValueOnce()/mockReturnValue() is called and no
-      // mockImplementation() is called after that.
+      // mockImplementationOnce()/mockImplementation() is called after that.
       // use the set return value.
@@ -234,6 +235,13 @@ if (isReturnValueLastSet) {
 
-      // If mockImplementation() is last set, or specific return values
-      // are used up, use the mock implementation.
-      if (mockImpl && returnValue === undefined) {
-        return mockImpl.apply(this, arguments);
+      // If mockImplementationOnce()/mockImplementation() is last set,
+      // or specific return values are used up, use the mock implementation.
+      let specificMockImpl;
+      if (returnValue === undefined) {
+        specificMockImpl = specificMockImpls.shift();
+        if (specificMockImpl === undefined) {
+          specificMockImpl = mockImpl;
+        }
+        if (specificMockImpl) {
+          return specificMockImpl.apply(this, arguments);
+        }
       }
@@ -273,2 +281,10 @@
 
+    f.mockImplementationOnce = fn => {
+      // next function call will use this mock implementation return value
+      // or default mock implementation return value
+      isReturnValueLastSet = false;
+      specificMockImpls.push(fn);
+      return f;
+    };
+
     f.mockImplementation = f.mockImpl = fn => {
@@ -342,3 +358,3 @@ // next function call will use mock implementation return value
 
-  const metadata = {type: type};
+  const metadata = {type};
   if (
@@ -345,0 +361,0 @@ type === 'constant' ||

No alert changes

Improved metrics

Total package byte prevSize

19675

increased by9.69%

Lines of code

536

increased by8.5%

Number of lines in readme file

118

increased by5.36%

No dependency changes