[Refactor] Use flatMap in LinesDiffContentToken

packages/cli-kit/src/private/node/content-tokens.test.ts

@@ -1,4 +1,5 @@
-import {LinkContentToken} from './content-tokens.js'
+import {LinkContentToken, LinesDiffContentToken} from './content-tokens.js'
+import colors from '../../public/node/colors.js'
 import {describe, expect, test} from 'vitest'
 
 describe('LinkContentToken', () => {
@@ -20,3 +21,33 @@ describe('LinkContentToken', () => {
     expect(got.output()).toEqual(fallback)
   })
 })
+
+describe('LinesDiffContentToken', () => {
+  test('formats added and removed lines correctly', () => {
+    // Given
+    const changes = [
+      {value: 'same\n', count: 1},
+      {value: 'removed\n', count: 1, removed: true},
+      {value: 'added\n', count: 1, added: true},
+    ]
+    const token = new LinesDiffContentToken(changes)
+
+    // When
+    const output = token.output()
+
+    // Then
+    expect(output).toEqual(['same\n', colors.magenta('- removed\n'), colors.green('+ added\n')])
+  })
+
+  test('handles multiple lines in a single change part', () => {
+    // Given
+    const changes = [{value: 'added1\nadded2\n', count: 2, added: true}]
+    const token = new LinesDiffContentToken(changes)
+
+    // When
+    const output = token.output()
+
+    // Then
+    expect(output).toEqual([colors.green('+ added1\n'), colors.green('+ added2\n')])
+  })
+})

packages/cli-kit/src/private/node/content-tokens.ts

@@ -63,27 +63,25 @@ export class JsonContentToken extends ContentToken<any> {
 
 export class LinesDiffContentToken extends ContentToken<Change[]> {
   output(): string[] {
-    return this.value
-      .map((part) => {
-        if (part.added) {
-          return part.value
-            .split(/\n/)
-            .filter((line) => line !== '')
-            .map((line) => {
-              return colors.green(`+ ${line}\n`)
-            })
-        } else if (part.removed) {
-          return part.value
-            .split(/\n/)
-            .filter((line) => line !== '')
-            .map((line) => {
-              return colors.magenta(`- ${line}\n`)
-            })
-        } else {
-          return part.value
-        }
-      })
-      .flat()
+    return this.value.flatMap((part) => {
+      if (part.added) {
+        return part.value
+          .split(/\n/)
+          .filter((line) => line !== '')
+          .map((line) => {
+            return colors.green(`+ ${line}\n`)
+          })
+      } else if (part.removed) {
+        return part.value
+          .split(/\n/)
+          .filter((line) => line !== '')
+          .map((line) => {
+            return colors.magenta(`- ${line}\n`)
+          })
+      } else {
+        return part.value
+      }
+    })
   }
 }