diff

package.json

@@ -50,6 +50,7 @@
     "@types/lodash": "^4.14.202",
     "cheerio": "^1.0.0",
     "dedent": "^1.5.1",
+    "diff": "^8.0.2",
     "eslint-plugin-markdown": "^4.0.1",
     "expect": "^29.7.0",
     "fp-ts": "^2.1.0",

src/rule.ts

@@ -1,16 +1,14 @@
 import {createHash} from 'crypto'
+import * as diff from 'diff'
 import type * as eslint from 'eslint'
-import expect from 'expect'
 import {tryCatch} from 'fp-ts/lib/Either'
 import {globSync} from 'glob'
 import * as jsYaml from 'js-yaml'
 import ms from 'ms'
 import * as os from 'os'
 import * as path from 'path'
-import stripAnsi from 'strip-ansi'
 import {dependencies} from './dependencies'
 import * as presetsModule from './presets'
-import {equivalentSimplified} from './simplify'
 
 export const codegen: eslint.Rule.RuleModule = {
   // @ts-expect-error types are wrong?
@@ -216,6 +214,27 @@ export const codegen: eslint.Rule.RuleModule = {
           return
         }
 
+        const patch = diff.createPatch(context.physicalFilename, existingContent.trimEnd(), result.right.trimEnd())
+        for (const parsedPatch of diff.parsePatch(patch)) {
+          for (const hunk of parsedPatch.hunks) {
+            let message = `Content doesn't match:\n`
+            message += hunk.lines.join('\n')
+            const startPosition = position(range[0])
+
+            const fix: Parameters<typeof context.report>[0]['fix'] = fixer =>
+              fixer.replaceTextRange(range, normalise(result.right) + os.EOL)
+            context.report({
+              message,
+              loc: {
+                start: {line: startPosition.line + hunk.oldStart, column: 0},
+                end: {line: startPosition.line + hunk.oldLines, column: 0},
+              },
+              fix,
+              // todo: fix or suggest based on an option
+            })
+          }
+        }
+        /*
         try {
           expect(normalise(existingContent)).toBe(normalise(result.right))
         } catch (e: unknown) {
@@ -231,6 +250,18 @@ export const codegen: eslint.Rule.RuleModule = {
             fix: fixer => fixer.replaceTextRange(range, normalise(result.right) + os.EOL),
           })
         }
+        */
+        // try {
+        //   expect(normalise(existingContent)).toBe(normalise(result.right))
+        // } catch (e: unknown) {
+        //   let message = `content doesn't match: ${e as string}`
+        //   if (process.env.NODE_ENV === 'test') message = stripAnsi(message)
+        //   context.report({
+        //     message,
+        //     loc: {start: position(range[0]), end: position(range[1])},
+        //     fix: fixer => fixer.replaceTextRange(range, normalise(result.right) + os.EOL),
+        //   })
+        // }
       })
     }