fix(jest-snapshot): always run prettier format a second time (#11560)

Author: G-Rath

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 ### Fixes
 
+- `[jest-snapshot]` Correctly indent inline snapshots ([#11560](https://github.com/facebook/jest/pull/11560))
+
 ### Chore & Maintenance
 
 ### Performance

e2e/__tests__/__snapshots__/toMatchInlineSnapshot.test.ts.snap

@@ -118,6 +118,20 @@ test('handles property matchers', () => {
 
 `;
 
+exports[`indentation is correct in the presences of existing snapshots, when the file is correctly formatted by prettier: existing snapshot 1`] = `
+it('is true', () => {
+  expect(true).toMatchInlineSnapshot(\`true\`);
+  expect([1, 2, 3]).toMatchInlineSnapshot(\`
+    Array [
+      1,
+      2,
+      3,
+    ]
+  \`);
+});
+
+`;
+
 exports[`indentation is correct in the presences of existing snapshots: existing snapshot 1`] = `
 test('existing snapshot', () => {
   expect({hello: 'world'}).toMatchInlineSnapshot(\`

e2e/__tests__/toMatchInlineSnapshot.test.ts

@@ -382,3 +382,20 @@ test('indentation is correct in the presences of existing snapshots', () => {
   expect(exitCode).toBe(0);
   expect(wrap(fileAfter)).toMatchSnapshot('existing snapshot');
 });
+
+test('indentation is correct in the presences of existing snapshots, when the file is correctly formatted by prettier', () => {
+  const filename = 'existing-snapshot.test.js';
+  const test = `
+    it('is true', () => {
+      expect(true).toMatchInlineSnapshot(\`true\`);
+      expect([1, 2, 3]).toMatchInlineSnapshot();
+    });\\n
+  `;
+
+  writeFiles(TESTS_DIR, {[filename]: test});
+  const {stderr, exitCode} = runJest(DIR, ['-w=1', '--ci=false', filename]);
+  const fileAfter = readFile(filename);
+  expect(stderr).toMatch('1 snapshot written from 1 test suite.');
+  expect(exitCode).toBe(0);
+  expect(wrap(fileAfter)).toMatchSnapshot('existing snapshot');
+});

packages/jest-snapshot/src/InlineSnapshots.ts

@@ -285,22 +285,19 @@ const runPrettier = (
   // Snapshots have now been inserted. Run prettier to make sure that the code is
   // formatted, except snapshot indentation. Snapshots cannot be formatted until
   // after the initial format because we don't know where the call expression
-  // will be placed (specifically its indentation).
-  let newSourceFile = prettier.format(sourceFileWithSnapshots, {
-    ...config,
-    filepath: sourceFilePath,
-  });
-
-  if (newSourceFile !== sourceFileWithSnapshots) {
-    // prettier moved things around, run it again to fix snapshot indentations.
-    newSourceFile = prettier.format(newSourceFile, {
+  // will be placed (specifically its indentation), so we have to do two
+  // prettier.format calls back-to-back.
+  return prettier.format(
+    prettier.format(sourceFileWithSnapshots, {
+      ...config,
+      filepath: sourceFilePath,
+    }),
+    {
       ...config,
       filepath: sourceFilePath,
       parser: createFormattingParser(snapshotMatcherNames, inferredParser),
-    });
-  }
-
-  return newSourceFile;
+    },
+  );
 };
 
 // This parser formats snapshots to the correct indentation.