feat: add sortSnapshots config option

README.md

@@ -106,12 +106,28 @@ You can update snapshot values
 SNAPSHOT_UPDATE=1 npm test
 ```
 
-If you want to sort saved snapshots alphabetically, run with
+## Sorted snapshots
+
+If you want to sort saved snapshots alphabetically inside each snapshot file, run with
 
 ```bash
 SNAPSHOT_SORT=1 npm test
 ```
 
+You can also set the config option in the package.json file
+
+```json
+{
+  "config": {
+    "snap-shot-it": {
+      "sortSnapshots": true
+    }
+  }
+}
+```
+
+Hopefully sorting snapshots would help when updating them.
+
 ## Named snapshots
 
 Renaming tests might lead to confusion and pruning snapshots. You can name the snapshots

src/e2e-spec.js

@@ -45,8 +45,13 @@ const checkSnapshots = (rootFolder, snapshots) => {
       'as file',
       filename
     )
+    // important: remove the loaded module from the cache to
+    // avoid a test using old data
     const loaded = require(filename)
+    delete require.cache[require.resolve(filename)]
+
     const expected = snapshots[expectedFilename]
+    // compare the values
     la(
       R.equals(loaded, expected),
       'in snapshot file',
@@ -56,6 +61,18 @@ const checkSnapshots = (rootFolder, snapshots) => {
       'from expected',
       expected
     )
+    // compare the order of snapshots
+    const savedOrder = Object.keys(loaded)
+    const expectedOrder = Object.keys(expected)
+    la(
+      R.equals(savedOrder, expectedOrder),
+      'in snapshot file',
+      filename,
+      'the order of snapshots is',
+      savedOrder,
+      'but expected order of snapshots to be',
+      expectedOrder
+    )
   })
 }
 
@@ -250,3 +267,80 @@ describe('custom pre-compare function', () => {
     })
   })
 })
+
+describe('sorted snapshots', () => {
+  // folder with specs to run
+  const sourceFolder = join(__dirname, '..', 'test-sorting')
+  // temp folder to copy to before running tests
+  const tempFolder = join(__dirname, '..', 'temp-sorting')
+
+  beforeEach(() => {
+    copyFolder(sourceFolder, tempFolder)
+  })
+
+  it('does not sort by default', function () {
+    this.timeout(5000)
+
+    execa.shellSync('npm test', {
+      cwd: tempFolder,
+      stdio: 'inherit',
+      // only use the limited environment keys
+      // without "CI=1" value
+      env: limitedEnv,
+      extendEnv: false
+    })
+
+    checkSnapshots(tempFolder, {
+      'spec.js': {
+        zz: 3,
+        bb: 2,
+        aa: 1
+      }
+    })
+
+    // run the tests again to check if values are not clashing
+    // but with CI=1 to avoid writing new files accidentally
+    execa.shellSync('npm test', {
+      cwd: tempFolder,
+      stdio: 'inherit',
+      env: { CI: '1' }
+    })
+  })
+
+  it('sorts with config parameter', function () {
+    this.timeout(5000)
+
+    const packageFilename = join(tempFolder, 'package.json')
+    const pkg = JSON.parse(fs.readFileSync(packageFilename, 'utf8'))
+    pkg.config['snap-shot-it'] = {
+      sortSnapshots: true
+    }
+    fs.writeFileSync(packageFilename, JSON.stringify(pkg, null, 2), 'utf8')
+
+    execa.shellSync('npm test', {
+      cwd: tempFolder,
+      stdio: 'inherit',
+      // only use the limited environment keys
+      // without "CI=1" value
+      env: limitedEnv,
+      extendEnv: false
+    })
+
+    // now the snapshots should be sorted
+    checkSnapshots(tempFolder, {
+      'spec.js': {
+        aa: 1,
+        bb: 2,
+        zz: 3
+      }
+    })
+
+    // run the tests again to check if values are not clashing
+    // but with CI=1 to avoid writing new files accidentally
+    execa.shellSync('npm test', {
+      cwd: tempFolder,
+      stdio: 'inherit',
+      env: { CI: '1' }
+    })
+  })
+})

src/utils.js

@@ -7,7 +7,8 @@ const defaults = {
   useRelativePath: false,
   'pre-compare': null,
   compare: null,
-  store: null
+  store: null,
+  sortSnapshots: false
 }
 /**
  * Pick only the keys we know about from whatever the user

test-sorting/README.md

@@ -0,0 +1,5 @@
+# test-custom-pre-fn
+
+This repo shows how `snap-shot-it` can load a custom pre-compare function via config in `package.json` file and use it to clean up data before comparing.
+
+See https://github.com/bahmutov/snap-shot-it/issues/350

test-sorting/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "test-custom-pre-fn",
+  "version": "1.0.0",
+  "description": "shows custom pre-compare function",
+  "main": "index.js",
+  "scripts": {
+    "test": "../node_modules/.bin/mocha 'specs/**/*.js'"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "config": {
+    "snap-shot-it": {}
+  }
+}

test-sorting/specs/spec.js

@@ -0,0 +1,9 @@
+const snapshot = require('../..')
+
+/* eslint-env mocha */
+it('has names in reverse order', () => {
+  // notice that snapshots are named NOT in sorted order
+  snapshot('zz', 3)
+  snapshot('bb', 2)
+  snapshot('aa', 1)
+})