From 3f9ca852d8d3d40cc3a662220d2e61aeae270ba2 Mon Sep 17 00:00:00 2001
From: Petter Nordholm <petter.nordholm@softhouse.se>
Date: Thu, 23 May 2019 22:40:05 +0200
Subject: [PATCH 1/3] Prevent drifting inline snapshots #8424

Fixes #8424 by avoiding indenting inline snapshot if second
line of inline snapshot already has been indented.
---
 .../src/__tests__/inline_snapshots.test.ts    | 50 +++++++++++++++++++
 .../jest-snapshot/src/inline_snapshots.ts     |  7 +++
 2 files changed, 57 insertions(+)

diff --git a/packages/jest-snapshot/src/__tests__/inline_snapshots.test.ts b/packages/jest-snapshot/src/__tests__/inline_snapshots.test.ts
index a6173b61cb86..68826b5aec2a 100644
--- a/packages/jest-snapshot/src/__tests__/inline_snapshots.test.ts
+++ b/packages/jest-snapshot/src/__tests__/inline_snapshots.test.ts
@@ -236,6 +236,56 @@ test('saveInlineSnapshots() indents multi-line snapshots with spaces', () => {
   );
 });
 
+test('saveInlineSnapshots() does not re-indent already indented snapshots', () => {
+  const filename = path.join(__dirname, 'my.test.js');
+  (fs.readFileSync as jest.Mock).mockImplementation(
+    () =>
+      "it('is a test', () => {\n" +
+      "  expect({a: 'a'}).toMatchInlineSnapshot();\n" +
+      '});\n' +
+      "it('is a another test', () => {\n" +
+      "  expect({a: 'a'}).toMatchInlineSnapshot(`\n" +
+      '    Object {\n' +
+      "      b: 'b'\n" +
+      '    }\n' +
+      '  `);\n' +
+      '});\n',
+  );
+  (prettier.resolveConfig.sync as jest.Mock).mockReturnValue({
+    bracketSpacing: false,
+    singleQuote: true,
+  });
+
+  saveInlineSnapshots(
+    [
+      {
+        frame: {column: 20, file: filename, line: 2} as Frame,
+        snapshot: `\nObject {\n  a: 'a'\n}\n`,
+      },
+    ],
+    prettier,
+    babelTraverse,
+  );
+
+  expect(fs.writeFileSync).toHaveBeenCalledWith(
+    filename,
+    "it('is a test', () => {\n" +
+      "  expect({a: 'a'}).toMatchInlineSnapshot(`\n" +
+      '    Object {\n' +
+      "      a: 'a'\n" +
+      '    }\n' +
+      '  `);\n' +
+      '});\n' +
+      "it('is a another test', () => {\n" +
+      "  expect({a: 'a'}).toMatchInlineSnapshot(`\n" +
+      '    Object {\n' +
+      "      b: 'b'\n" +
+      '    }\n' +
+      '  `);\n' +
+      '});\n',
+  );
+});
+
 test('saveInlineSnapshots() indents multi-line snapshots with tabs', () => {
   const filename = path.join(__dirname, 'my.test.js');
   (fs.readFileSync as jest.Mock).mockImplementation(
diff --git a/packages/jest-snapshot/src/inline_snapshots.ts b/packages/jest-snapshot/src/inline_snapshots.ts
index ec2612ae2ce6..2f9a931dd317 100644
--- a/packages/jest-snapshot/src/inline_snapshots.ts
+++ b/packages/jest-snapshot/src/inline_snapshots.ts
@@ -120,6 +120,13 @@ const groupSnapshotsByFile = groupSnapshotsBy(({frame: {file}}) => file);
 
 const indent = (snapshot: string, numIndents: number, indentation: string) => {
   const lines = snapshot.split('\n');
+  if (
+    lines.length > 2 &&
+    lines[1].startsWith(indentation.repeat(numIndents + 1))
+  ) {
+    return snapshot;
+  }
+
   return lines
     .map((line, index) => {
       if (index === 0) {

From ef5a9e3cbe8790c2edc0848849dfbc20ff56307a Mon Sep 17 00:00:00 2001
From: Petter Nordholm <petter.nordholm@softhouse.se>
Date: Fri, 24 May 2019 09:49:46 +0200
Subject: [PATCH 2/3] Added pull request to changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ea66aee969ad..dbfe4d39602f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 
 - `[babel-plugin-jest-hoist]` Expand list of whitelisted globals in global mocks ([#8429](https://github.com/facebook/jest/pull/8429)
 - `[jest-core]` Make watch plugin initialization errors look nice ([#8422](https://github.com/facebook/jest/pull/8422))
+- `[jest-snapshot]` Prevent inline snapshots from drifting when inline snapshots are updated ([#8492](https://github.com/facebook/jest/pull/8492))
 
 ### Chore & Maintenance
 

From 9c92314f593bf2657582cdbe52418e2f06f1d98d Mon Sep 17 00:00:00 2001
From: Petter Nordholm <petter.nordholm@softhouse.se>
Date: Sat, 25 May 2019 10:38:29 +0200
Subject: [PATCH 3/3] Fixed review comment

Also added a short comment to the code describing its purpose.
---
 packages/jest-snapshot/src/inline_snapshots.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/jest-snapshot/src/inline_snapshots.ts b/packages/jest-snapshot/src/inline_snapshots.ts
index 2f9a931dd317..8b3e38afcc28 100644
--- a/packages/jest-snapshot/src/inline_snapshots.ts
+++ b/packages/jest-snapshot/src/inline_snapshots.ts
@@ -120,8 +120,9 @@ const groupSnapshotsByFile = groupSnapshotsBy(({frame: {file}}) => file);
 
 const indent = (snapshot: string, numIndents: number, indentation: string) => {
   const lines = snapshot.split('\n');
+  // Prevent re-identation of inline snapshots.
   if (
-    lines.length > 2 &&
+    lines.length >= 2 &&
     lines[1].startsWith(indentation.repeat(numIndents + 1))
   ) {
     return snapshot;