Stop the lint pipeline from reporting issues it re-creates itself

packages/host/app/tools/patch-code.ts

@@ -66,32 +66,52 @@ export default class PatchCodeTool extends HostBaseTool<
         lintIssues = lintResult.lintIssues ?? [];
       }
 
-      finalFileIdentifier = await this.determineFinalFileUrl(
-        fileUrl,
-        fileInfo,
-        hasEmptySearchPortion,
-      );
+      // An applied patch always changed the pre-lint content, so ending up
+      // back at the original file means the autofix/format pass reverted
+      // the whole edit. Re-patching can never make progress from here —
+      // any further attempt round-trips to this same content — so say so
+      // alongside the lint issues instead of writing a no-op save that
+      // would keep the model trying.
+      let revertedByFormatter =
+        sourceContent !== '' && patchedCode === sourceContent;
+      if (revertedByFormatter) {
+        lintIssues = [
+          ...lintIssues,
+          'The automatic formatter reverted the applied changes, so the file is unchanged. Reformatting-only patches cannot fix the remaining issues; change the content itself or leave it as is.',
+        ];
+      } else {
+        finalFileIdentifier = await this.determineFinalFileUrl(
+          fileUrl,
+          fileInfo,
+          hasEmptySearchPortion,
+        );
 
-      let clientRequestId = this.toolService.trackAiAssistantCardRequest({
-        action: 'patch-code',
-        roomId,
-        fileUrl: finalFileIdentifier,
-      });
+        let clientRequestId = this.toolService.trackAiAssistantCardRequest({
+          action: 'patch-code',
+          roomId,
+          fileUrl: finalFileIdentifier,
+        });
 
-      let savedThroughOpenFile = await this.trySaveThroughOpenFile(
-        finalFileIdentifier,
-        patchedCode,
-        clientRequestId,
-      );
-      if (!savedThroughOpenFile) {
-        this.cardService
-          .saveSource(new URL(finalFileIdentifier), patchedCode, 'bot-patch', {
-            resetLoader: hasExecutableExtension(finalFileIdentifier),
-            clientRequestId,
-          })
-          .catch((error: unknown) => {
-            console.error('PatchCodeTool: failed to save source', error);
-          });
+        let savedThroughOpenFile = await this.trySaveThroughOpenFile(
+          finalFileIdentifier,
+          patchedCode,
+          clientRequestId,
+        );
+        if (!savedThroughOpenFile) {
+          this.cardService
+            .saveSource(
+              new URL(finalFileIdentifier),
+              patchedCode,
+              'bot-patch',
+              {
+                resetLoader: hasExecutableExtension(finalFileIdentifier),
+                clientRequestId,
+              },
+            )
+            .catch((error: unknown) => {
+              console.error('PatchCodeTool: failed to save source', error);
+            });
+        }
       }
     }
 

packages/realm-server/tests/realm-endpoints/lint-test.ts

@@ -621,6 +621,46 @@ export class MyCard extends CardDef {
       );
     });
 
+    test('does not flag the whitespace prettier introduces by wrapping long text', async function (assert) {
+      // Prettier wraps text nodes longer than its print width across
+      // indented lines; no-whitespace-for-layout flags exactly that wrap and
+      // has no autofix, so reporting it would hand back an issue no edit can
+      // clear — the formatter reverts every attempted whitespace fix.
+      let longText =
+        'WELCOME TO MY HOMEPAGE     HOT SITE AWARD WINNER     BEST VIEWED IN 800x600    ';
+      let response = await request
+        .post('/_lint')
+        .set(
+          'Authorization',
+          `Bearer ${createJWT(testRealm, 'john', ['read', 'write'])}`,
+        )
+        .set('X-HTTP-Method-Override', 'QUERY')
+        .set('Accept', 'application/json')
+        .send(`import { CardDef } from '@cardstack/base/card-api';
+export class MyCard extends CardDef {
+}
+<template>
+  <div class='marquee'>
+    <span>${longText}</span>
+  </div>
+</template>
+`);
+
+      assert.strictEqual(response.status, 200, 'HTTP 200 status');
+      let responseJson = JSON.parse(response.text);
+      assert.ok(
+        /<span>[^<]*\n[^<]*<\/span>/.test(responseJson.output),
+        'prettier wrapped the long text node across lines',
+      );
+      let whitespaceMessage = responseJson.messages.find(
+        (m: any) => m.ruleId === 'no-whitespace-for-layout',
+      );
+      assert.notOk(
+        whitespaceMessage,
+        'no-whitespace-for-layout is not reported for formatter-introduced wrapping',
+      );
+    });
+
     test('handles nested template structures correctly', async function (assert) {
       let response = await request
         .post('/_lint')

packages/runtime-common/tasks/lint.ts

@@ -155,7 +155,24 @@ async function initTemplateLinter(): Promise<any> {
   const hostRequire = Module.createRequire(resolve(HOST_PKG, 'package.json'));
   const tlModule = hostRequire('ember-template-lint');
   const TemplateLinter = (tlModule as any).default ?? tlModule;
-  return new TemplateLinter({ workingDir: HOST_PKG });
+  // Host's config, minus rules the rest of this pipeline contradicts.
+  // Prettier (the pass right before template-lint) wraps text nodes longer
+  // than its print width across indented lines; no-whitespace-for-layout
+  // flags exactly that wrap and has no autofix, so for any over-width text
+  // node the pipeline would report an error that no edit can clear — the
+  // formatter reverts every attempted whitespace fix. The wrapped whitespace
+  // collapses at render, so nothing is lost by not flagging it.
+  const hostTemplateLintConfig = hostRequire('./.template-lintrc.js');
+  return new TemplateLinter({
+    workingDir: HOST_PKG,
+    config: {
+      ...hostTemplateLintConfig,
+      rules: {
+        ...hostTemplateLintConfig.rules,
+        'no-whitespace-for-layout': false,
+      },
+    },
+  });
 }
 
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