From 505065457952d8eb34bbce6ce1753e1065ede1c1 Mon Sep 17 00:00:00 2001
From: Mark Pedrotti <pedrottimark@gmail.com>
Date: Wed, 13 Feb 2019 09:23:26 -0500
Subject: [PATCH] expect: Improve report when matcher fails, part 8 (#7876)

---
 CHANGELOG.md                                  |   1 +
 .../__snapshots__/matchers.test.js.snap       | 175 +++++++++++-------
 packages/expect/src/matchers.js               |  54 ++++--
 3 files changed, 148 insertions(+), 82 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 075bb36680ac..5c70ac4f9656 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ### Features
 
 - `[expect]`: Improve report when matcher fails, part 7 ([#7866](https://github.com/facebook/jest/pull/7866))
+- `[expect]`: Improve report when matcher fails, part 8 ([#7876](https://github.com/facebook/jest/pull/7876))
 
 ### Fixes
 
diff --git a/packages/expect/src/__tests__/__snapshots__/matchers.test.js.snap b/packages/expect/src/__tests__/__snapshots__/matchers.test.js.snap
index 1ab89d930b1b..fa555849d062 100644
--- a/packages/expect/src/__tests__/__snapshots__/matchers.test.js.snap
+++ b/packages/expect/src/__tests__/__snapshots__/matchers.test.js.snap
@@ -389,139 +389,178 @@ Received: <red>true</>"
 `;
 
 exports[`.toBeCloseTo() {pass: false} expect(-Infinity)toBeCloseTo( -1.23) 1`] = `
-"<dim>expect(</><red>received</><dim>).toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
 
-Precision: <green>2</>-digit
-Expected:  <green>-1.23</>
-Received:  <red>-Infinity</>"
+Expected: <green>-1.23</>
+Received: <red>-Infinity</>
+
+Expected precision:    <green>2</>
+Expected difference: < <green>0.005</>
+Received difference:   <red>Infinity</>"
 `;
 
 exports[`.toBeCloseTo() {pass: false} expect(Infinity)toBeCloseTo( -Infinity) 1`] = `
-"<dim>expect(</><red>received</><dim>).toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
+
+Expected: <green>-Infinity</>
+Received: <red>Infinity</>
 
-Precision: <green>2</>-digit
-Expected:  <green>-Infinity</>
-Received:  <red>Infinity</>"
+Expected precision:    <green>2</>
+Expected difference: < <green>0.005</>
+Received difference:   <red>Infinity</>"
 `;
 
 exports[`.toBeCloseTo() {pass: false} expect(Infinity)toBeCloseTo( 1.23) 1`] = `
-"<dim>expect(</><red>received</><dim>).toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
+
+Expected: <green>1.23</>
+Received: <red>Infinity</>
 
-Precision: <green>2</>-digit
-Expected:  <green>1.23</>
-Received:  <red>Infinity</>"
+Expected precision:    <green>2</>
+Expected difference: < <green>0.005</>
+Received difference:   <red>Infinity</>"
 `;
 
 exports[`.toBeCloseTo() {pass: true} expect(-Infinity)toBeCloseTo( -Infinity) 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
 
-Precision: <green>2</>-digit
-Expected:  <green>-Infinity</>
-Received:  <red>-Infinity</>"
+Expected: not <green>-Infinity</>
+"
 `;
 
 exports[`.toBeCloseTo() {pass: true} expect(0)toBeCloseTo( 0) 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
 
-Precision: <green>2</>-digit
-Expected:  <green>0</>
-Received:  <red>0</>"
+Expected: not <green>0</>
+"
 `;
 
 exports[`.toBeCloseTo() {pass: true} expect(0)toBeCloseTo( 0.001) 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
 
-Precision: <green>2</>-digit
-Expected:  <green>0.001</>
-Received:  <red>0</>"
+Expected: not <green>0.001</>
+Received:     <red>0</>
+
+Expected precision:        <green>2</>
+Expected difference: not < <green>0.005</>
+Received difference:       <red>0.001</>"
 `;
 
 exports[`.toBeCloseTo() {pass: true} expect(1.23)toBeCloseTo( 1.225) 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
+
+Expected: not <green>1.225</>
+Received:     <red>1.23</>
 
-Precision: <green>2</>-digit
-Expected:  <green>1.225</>
-Received:  <red>1.23</>"
+Expected precision:        <green>2</>
+Expected difference: not < <green>0.005</>
+Received difference:       <red>0.004999999999999893</>"
 `;
 
 exports[`.toBeCloseTo() {pass: true} expect(1.23)toBeCloseTo( 1.226) 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
 
-Precision: <green>2</>-digit
-Expected:  <green>1.226</>
-Received:  <red>1.23</>"
+Expected: not <green>1.226</>
+Received:     <red>1.23</>
+
+Expected precision:        <green>2</>
+Expected difference: not < <green>0.005</>
+Received difference:       <red>0.0040000000000000036</>"
 `;
 
 exports[`.toBeCloseTo() {pass: true} expect(1.23)toBeCloseTo( 1.229) 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
+
+Expected: not <green>1.229</>
+Received:     <red>1.23</>
 
-Precision: <green>2</>-digit
-Expected:  <green>1.229</>
-Received:  <red>1.23</>"
+Expected precision:        <green>2</>
+Expected difference: not < <green>0.005</>
+Received difference:       <red>0.0009999999999998899</>"
 `;
 
 exports[`.toBeCloseTo() {pass: true} expect(1.23)toBeCloseTo( 1.234) 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
 
-Precision: <green>2</>-digit
-Expected:  <green>1.234</>
-Received:  <red>1.23</>"
+Expected: not <green>1.234</>
+Received:     <red>1.23</>
+
+Expected precision:        <green>2</>
+Expected difference: not < <green>0.005</>
+Received difference:       <red>0.0040000000000000036</>"
 `;
 
 exports[`.toBeCloseTo() {pass: true} expect(Infinity)toBeCloseTo( Infinity) 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
 
-Precision: <green>2</>-digit
-Expected:  <green>Infinity</>
-Received:  <red>Infinity</>"
+Expected: not <green>Infinity</>
+"
 `;
 
 exports[`.toBeCloseTo() accepts an optional precision argument: [0, 0.000004, 5] 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>, </><green>precision</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>, </><green>precision</><dim>)</>
 
-Precision: <green>5</>-digit
-Expected:  <green>0.000004</>
-Received:  <red>0</>"
+Expected: not <green>0.000004</>
+Received:     <red>0</>
+
+Expected precision:        <green>5</>
+Expected difference: not < <green>0.000005</>
+Received difference:       <red>0.000004</>"
 `;
 
 exports[`.toBeCloseTo() accepts an optional precision argument: [0, 0.0001, 3] 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>, </><green>precision</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>, </><green>precision</><dim>)</>
+
+Expected: not <green>0.0001</>
+Received:     <red>0</>
 
-Precision: <green>3</>-digit
-Expected:  <green>0.0001</>
-Received:  <red>0</>"
+Expected precision:        <green>3</>
+Expected difference: not < <green>0.0005</>
+Received difference:       <red>0.0001</>"
 `;
 
 exports[`.toBeCloseTo() accepts an optional precision argument: [0, 0.1, 0] 1`] = `
-"<dim>expect(</><red>received</><dim>).</>not<dim>.toBeCloseTo(</><green>expected</><dim>, </><green>precision</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>not<dim>.</>toBeCloseTo<dim>(</><green>expected</><dim>, </><green>precision</><dim>)</>
 
-Precision: <green>0</>-digit
-Expected:  <green>0.1</>
-Received:  <red>0</>"
+Expected: not <green>0.1</>
+Received:     <red>0</>
+
+Expected precision:        <green>0</>
+Expected difference: not < <green>0.5</>
+Received difference:       <red>0.1</>"
 `;
 
 exports[`.toBeCloseTo() throws: [0, 0.01] 1`] = `
-"<dim>expect(</><red>received</><dim>).toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
+
+Expected: <green>0.01</>
+Received: <red>0</>
 
-Precision: <green>2</>-digit
-Expected:  <green>0.01</>
-Received:  <red>0</>"
+Expected precision:    <green>2</>
+Expected difference: < <green>0.005</>
+Received difference:   <red>0.01</>"
 `;
 
 exports[`.toBeCloseTo() throws: [1, 1.23] 1`] = `
-"<dim>expect(</><red>received</><dim>).toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
 
-Precision: <green>2</>-digit
-Expected:  <green>1.23</>
-Received:  <red>1</>"
+Expected: <green>1.23</>
+Received: <red>1</>
+
+Expected precision:    <green>2</>
+Expected difference: < <green>0.005</>
+Received difference:   <red>0.22999999999999998</>"
 `;
 
 exports[`.toBeCloseTo() throws: [1.23, 1.2249999] 1`] = `
-"<dim>expect(</><red>received</><dim>).toBeCloseTo(</><green>expected</><dim>)</>
+"<dim>expect(</><red>received</><dim>).</>toBeCloseTo<dim>(</><green>expected</><dim>)</>
+
+Expected: <green>1.2249999</>
+Received: <red>1.23</>
 
-Precision: <green>2</>-digit
-Expected:  <green>1.2249999</>
-Received:  <red>1.23</>"
+Expected precision:    <green>2</>
+Expected difference: < <green>0.005</>
+Received difference:   <red>0.005000099999999952</>"
 `;
 
 exports[`.toBeDefined(), .toBeUndefined() '"a"' is defined 1`] = `
diff --git a/packages/expect/src/matchers.js b/packages/expect/src/matchers.js
index 844d6fc1b986..bc093152ca15 100644
--- a/packages/expect/src/matchers.js
+++ b/packages/expect/src/matchers.js
@@ -87,25 +87,51 @@ const matchers: MatchersObject = {
     return {actual: received, expected, message, name: 'toBe', pass};
   },
 
-  toBeCloseTo(actual: number, expected: number, precision?: number = 2) {
+  toBeCloseTo(received: number, expected: number, precision?: number = 2) {
     const secondArgument = arguments.length === 3 ? 'precision' : null;
-    ensureNumbers(actual, expected, '.toBeCloseTo');
+    const isNot = this.isNot;
+    const options = {
+      isNot,
+      promise: this.promise,
+      secondArgument,
+    };
+    ensureNumbers(received, expected, '.toBeCloseTo');
 
     let pass = false;
+    let expectedDiff = 0;
+    let receivedDiff = 0;
 
-    if (actual == Infinity && expected == Infinity) pass = true;
-    else if (actual == -Infinity && expected == -Infinity) pass = true;
-    else pass = Math.abs(expected - actual) < Math.pow(10, -precision) / 2;
+    if (received === Infinity && expected === Infinity) {
+      pass = true; // Infinity - Infinity is NaN
+    } else if (received === -Infinity && expected === -Infinity) {
+      pass = true; // -Infinity - -Infinity is NaN
+    } else {
+      expectedDiff = Math.pow(10, -precision) / 2;
+      receivedDiff = Math.abs(expected - received);
+      pass = receivedDiff < expectedDiff;
+    }
 
-    const message = () =>
-      matcherHint('.toBeCloseTo', undefined, undefined, {
-        isNot: this.isNot,
-        secondArgument,
-      }) +
-      '\n\n' +
-      `Precision: ${printExpected(precision)}-digit\n` +
-      `Expected:  ${printExpected(expected)}\n` +
-      `Received:  ${printReceived(actual)}`;
+    const message = pass
+      ? () =>
+          matcherHint('toBeCloseTo', undefined, undefined, options) +
+          '\n\n' +
+          `Expected: not ${printExpected(expected)}\n` +
+          (receivedDiff === 0
+            ? ''
+            : `Received:     ${printReceived(received)}\n` +
+              '\n' +
+              `Expected precision:        ${printExpected(precision)}\n` +
+              `Expected difference: not < ${printExpected(expectedDiff)}\n` +
+              `Received difference:       ${printReceived(receivedDiff)}`)
+      : () =>
+          matcherHint('toBeCloseTo', undefined, undefined, options) +
+          '\n\n' +
+          `Expected: ${printExpected(expected)}\n` +
+          `Received: ${printReceived(received)}\n` +
+          '\n' +
+          `Expected precision:    ${printExpected(precision)}\n` +
+          `Expected difference: < ${printExpected(expectedDiff)}\n` +
+          `Received difference:   ${printReceived(receivedDiff)}`;
 
     return {message, pass};
   },