Issue #5197: Add descriptive error to Expect CalledWith methods when …

…missing optional arguments (#5547)

CHANGELOG.md

@@ -13,6 +13,8 @@
 
 ### Fixes
 
+* `[expect]` Add descriptive error message to CalledWith methods when missing
+ optional arguments ([#5547](https://github.com/facebook/jest/pull/5547))
 * `[jest-cli]` Fix inability to quit watch mode while debugger is still attached
  ([#5029](https://github.com/facebook/jest/pull/5029))
 * `[jest-haste-map]` Properly handle platform-specific file deletions

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

@@ -79,6 +79,13 @@ Expected mock function to have been last called with:
  <green>\\"bar\\"</> as argument 2, but it was called with <red>\\"bar3\\"</>."
 `;
 
+exports[`lastCalledWith works with trailing undefined arguments 1`] = `
+"<dim>expect(</><red>jest.fn()</><dim>).lastCalledWith(</><green>expected</><dim>)</>
+
+Expected mock function to have been last called with:
+ Did not expect argument 2 but it was called with <red>undefined</>."
+`;
+
 exports[`toBeCalled works only on spies or jest.fn 1`] = `
 "<dim>expect(</><red>jest.fn()</><dim>)[.not].toBeCalled(</><dim>)</>
 
@@ -302,6 +309,13 @@ Expected mock function to have been called with:
  <green>\\"bar\\"</> as argument 2, but it was called with <red>\\"bar1\\"</>."
 `;
 
+exports[`toHaveBeenCalledWith works with trailing undefined arguments 1`] = `
+"<dim>expect(</><red>jest.fn()</><dim>).toHaveBeenCalledWith(</><green>expected</><dim>)</>
+
+Expected mock function to have been called with:
+ Did not expect argument 2 but it was called with <red>undefined</>."
+`;
+
 exports[`toHaveBeenLastCalledWith works only on spies or jest.fn 1`] = `
 "<dim>expect(</><red>jest.fn()</><dim>)[.not].toHaveBeenLastCalledWith(</><dim>)</>
 
@@ -380,3 +394,10 @@ exports[`toHaveBeenLastCalledWith works with many arguments that don't match 1`]
 Expected mock function to have been last called with:
  <green>\\"bar\\"</> as argument 2, but it was called with <red>\\"bar3\\"</>."
 `;
+
+exports[`toHaveBeenLastCalledWith works with trailing undefined arguments 1`] = `
+"<dim>expect(</><red>jest.fn()</><dim>).toHaveBeenLastCalledWith(</><green>expected</><dim>)</>
+
+Expected mock function to have been last called with:
+ Did not expect argument 2 but it was called with <red>undefined</>."
+`;

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

@@ -164,6 +164,15 @@ describe('toHaveBeenCalledTimes', () => {
  ).toThrowErrorMatchingSnapshot();
  });
 
+ test(`${calledWith} works with trailing undefined arguments`, () => {
+ const fn = jest.fn();
+ fn('foo', undefined);
+
+ expect(() =>
+ jestExpect(fn)[calledWith]('foo'),
+ ).toThrowErrorMatchingSnapshot();
+ });
+
  test(`${calledWith} works with Map`, () => {
  const fn = jest.fn();
 

packages/expect/src/spy_matchers.js

@@ -219,8 +219,14 @@ const formatMismatchedArgs = (expected, received) => {
  ` ${printExpected(expected[i])} as argument ${i + 1}, ` +
  `but it was called with ${printReceived(received[i])}.`,
  );
+ } else if (i >= expected.length) {
+ printedArgs.push(
+ ` Did not expect argument ${i + 1} ` +
+ `but it was called with ${printReceived(received[i])}.`,
+ );
  }
  }
+
  return printedArgs.join('\n');
 };