Added matchers .toBeCloseTo and .toMatch

jestjs · Jul 10, 2016 · 0d1052c · 0d1052c
1 parent 404635e
commit 0d1052c
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Showing 4 changed files with 118 additions and 3 deletions.
diff --git a/packages/jest-matchers/src/__tests__/matchers-test.js b/packages/jest-matchers/src/__tests__/matchers-test.js
@@ -91,3 +91,84 @@ describe('.toBeNaN()', () => {
     });
   });
 });
+
+describe('.toBeCloseTo()', () => {
+  it('passes', () => {
+    [
+      [0, 0],
+      [0, 0.001],
+      [1.23, 1.229],
+      [1.23, 1.226],
+      [1.23, 1.225],
+      [1.23, 1.234],
+    ].forEach(([n1, n2]) => {
+      jestExpect(n1).toBeCloseTo(n2);
+      expect(() => jestExpect(n1).not.toBeCloseTo(n2))
+        .toThrowError(/not to be close to/);
+    });
+  });
+
+  it('throws', () => {
+    [
+      [0, 0.01],
+      [1, 1.23],
+      [1.23, 1.2249999],
+    ].forEach(([n1, n2]) => {
+      expect(() => jestExpect(n1).toBeCloseTo(n2))
+        .toThrowError(/to be close to/);
+      jestExpect(n1).not.toBeCloseTo(n2);
+    });
+  });
+
+  it('accepts an optional precision argument', () => {
+    [
+      [0, 0.1, 0],
+      [0, 0.0001, 3],
+    ].forEach(([n1, n2, p]) => {
+      jestExpect(n1).toBeCloseTo(n2, p);
+      expect(() => jestExpect(n1).not.toBeCloseTo(n2, p))
+        .toThrowError(/not to be close to/);
+    });
+  });
+});
+
+describe('.toMatch()', () => {
+  it('passes', () => {
+    [
+      [/foo/, /foo/],
+      ['foo', 'foo'],
+      ['foo', /foo/],
+    ].forEach(([n1, n2]) => {
+      jestExpect(n1).toMatch(n2);
+      expect(() => jestExpect(n1).not.toMatch(n2))
+        .toThrowError(/not to match/);
+    });
+  });
+
+  it('throws', () => {
+    [
+      [/bar/, /foo/],
+      ['bar', 'foo'],
+      ['bar', /foo/],
+    ].forEach(([n1, n2]) => {
+      expect(() => jestExpect(n1).toMatch(n2))
+        .toThrowError(/to match/);
+      jestExpect(n1).not.toMatch(n2);
+    });
+  });
+
+  it('throws for non string/regex expected value' , () => {
+    [
+      ['foo', 1],
+      ['foo', {}],
+      ['foo', []],
+      ['foo', true],
+      ['foo', () => {}],
+      ['foo', undefined],
+    ].forEach(([n1, n2]) => {
+      expect(() => jestExpect(n1).toMatch(n2))
+        .toThrowError(/is not a String or a RegExp/);
+      jestExpect(n1).not.toMatch(n2);
+    })
+  })
+});
diff --git a/packages/jest-matchers/src/index.js b/packages/jest-matchers/src/index.js
@@ -31,10 +31,11 @@ function makeThrowingMatcher(
   isNot: boolean,
   actual: any,
 ): ThrowingMatcherFn {
-  return function throwingMatcher(expected) {
+  return function throwingMatcher(expected, options) {
     const result: ExpectationResult = matcher(
       actual,
       expected,
+      options,
       {args: arguments},
     );
 

diff --git a/packages/jest-matchers/src/matchers.js b/packages/jest-matchers/src/matchers.js
@@ -16,7 +16,7 @@ const diff = require('jest-diff');
 const stringify = require('./utils').stringify;
 
 const matchers: MatchersObject = {
-  toBe(actual: any, expected: number): ExpectationResult {
+  toBe(actual: any, expected: number) {
     const pass = actual === expected;
 
     if (pass) {
@@ -69,6 +69,34 @@ const matchers: MatchersObject = {
 
     return {message, pass};
   },
+
+  toBeCloseTo(actual: number, expected: number, precision: number) {
+    if (precision !== 0) {
+      precision = precision || 2;
+    }
+    const pass = Math.abs(expected - actual) < (Math.pow(10, -precision) / 2);
+    const message = pass
+      ? () => `expected '${actual}' not to be close to '${expected}'`
+      : () => `expected '${actual}' to be close to '${expected}'`;
+
+    return {message, pass};
+  },
+
+  toMatch(actual: any, expected: string) {
+    if (!(expected instanceof RegExp) && !(typeof expected == 'string')) {
+      return {
+        pass: false,
+        message: `expected '${expected}' is not a String or a RegExp`,
+      };
+    }
+
+    const pass = new RegExp(expected).test(actual);
+    const message = pass
+      ? () => `expected '${actual}' not to match '${expected}'`
+      : () => `expected '${actual}' to match '${expected}'`;
+
+    return {message, pass};
+  },
 };
 
 function ensureNoExpected(expected, matcherName) {

diff --git a/packages/jest-matchers/types.js b/packages/jest-matchers/types.js
@@ -14,6 +14,11 @@ export type ExpectationResult = {
   message: string | () => string,
 };
 
-export type RawMatcherFn = (expected?: any, actual: any) => ExpectationResult;
+export type RawMatcherFn = (
+  expected: any,
+  actual: any,
+  options: any,
+) => ExpectationResult;
+
 export type ThrowingMatcherFn = (actual: any) => void;
 export type MatchersObject = {[id:string]: RawMatcherFn};