[expect]: add empty string check to toThrow matcher

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## master
 
+## Fixes
+
+- `[expect]` Add empty string check to `toThrow` matcher ([#6836](https://github.com/facebook/jest/pull/6836))
+
 ## 23.5.0
 
 ### Features

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

@@ -28,6 +28,16 @@ Instead, it threw:
 <red>      <dim>at jestExpect (</>packages/expect/src/__tests__/toThrowMatchers-test.js<dim>:24:74)</></>"
 `;
 
+exports[`.toThrow() fails when given an empty string 1`] = `
+"<dim>expect(</><red>function</><dim>).toThrow(</><green>string</><dim>)</>
+
+Expected the function to throw an error matching:
+  <green>\\"\\"</>
+Instead, it threw:
+<red>  apple</>
+<red>      <dim>at toThrowMatchingStringOrRegexp (</>packages/expect/src/to_throw_matchers.js<dim>:109:13)</></>"
+`;
+
 exports[`.toThrow() invalid actual 1`] = `
 "<dim>expect(</><red>function</><dim>).toThrow(</><green>undefined</><dim>)</>
 
@@ -153,6 +163,16 @@ Instead, it threw:
 <red>      <dim>at jestExpect (</>packages/expect/src/__tests__/toThrowMatchers-test.js<dim>:24:74)</></>"
 `;
 
+exports[`.toThrowError() fails when given an empty string 1`] = `
+"<dim>expect(</><red>function</><dim>).toThrow(</><green>string</><dim>)</>
+
+Expected the function to throw an error matching:
+  <green>\\"\\"</>
+Instead, it threw:
+<red>  apple</>
+<red>      <dim>at toThrowMatchingStringOrRegexp (</>packages/expect/src/to_throw_matchers.js<dim>:109:13)</></>"
+`;
+
 exports[`.toThrowError() invalid actual 1`] = `
 "<dim>expect(</><red>function</><dim>).toThrowError(</><green>undefined</><dim>)</>
 

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

@@ -28,6 +28,12 @@ class customError extends Error {
     class Err extends customError {}
     class Err2 extends customError {}
 
+    test('fails when given an empty string', () => {
+      expect(() => jestExpect(() => {
+        throw 'apple';
+      }).toThrow('')).toThrowErrorMatchingSnapshot();
+    });
+
     test('to throw or not to throw', () => {
       jestExpect(() => {
         throw new customError('apple');

packages/expect/src/to_throw_matchers.js

@@ -109,7 +109,7 @@ const toThrowMatchingStringOrRegexp = (
     error = new Error(error);
   }
 
-  const pass = !!(error && error.message.match(pattern));
+  const pass = !!(error && value && error.message.match(pattern));
   const message = pass
     ? () =>
         matcherHint('.not' + name, 'function', getType(value)) +