Adds integrity check of formatter as a CI/CD step

.github/workflows/formatting-integrity-check.yaml

@@ -0,0 +1,31 @@
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'packages/language-support/src/formatting/**'
+
+  pull_request:
+    branches:
+      - main
+    paths:
+      - 'packages/language-support/src/formatting/**'
+
+jobs:
+  formatting-integrity-check:
+    name: Formatter integrity check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup antlr4
+        uses: ./.github/actions/setup-antlr4
+
+      - name: Install dependencies with frozen lock file and generate parser
+        run: npm ci
+
+      - name: Build Project
+        run: npm run build
+
+      - name: Run formatting check
+        run: npm run test:formattingIntegrity

package.json

@@ -21,6 +21,7 @@
     "watch": "turbowatch ./turbowatch.ts",
     "test": "turbo run test",
     "test:e2e": "turbo run test:e2e",
+    "test:formattingIntegrity": "ts-node ./packages/language-support/src/tests/formatting/verification/verificationCheck.ts",
     "dev-codemirror": "turbo run @neo4j-cypher/react-codemirror-playground#dev",
     "lint": "eslint . --ext .ts",
     "lint-fix": "eslint . --fix --ext .ts",

packages/language-support/src/tests/formatting/verification/verificationCheck.ts

@@ -0,0 +1,53 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import { formatQuery } from '../../../formatting/formatting';
+import { standardizeQuery } from '../../../formatting/standardizer';
+
+function throwError(message: string, query: string, formatted: string): never {
+  throw new Error(`${message},
+---------   QUERY BEFORE START  ------------
+${query}
+---------   QUERY BEFORE END    ----------
+
+---------   QUERY FORMATTED START  ------------
+${formatted}
+---------   QUERY FORMATTED END    ----------
+`);
+}
+
+function verifyFormatting(query: string): void {
+  const formatted = formatQuery(query);
+  const queryStandardized = standardizeQuery(query);
+  const formattedStandardized = standardizeQuery(formatted);
+  const originalNonWhitespaceCount = query.replace(/\s/g, '').length;
+  const formattedNonWhitespaceCount = formatted.replace(/\s/g, '').length;
+
+  // Non-whitespace character count check
+  if (originalNonWhitespaceCount !== formattedNonWhitespaceCount) {
+    throwError('Non-whitespace character count mismatch', query, formatted);
+  }
+
+  // AST integrity check
+  if (formattedStandardized !== queryStandardized) {
+    throwError(
+      'Standardized query does not match standardized formatted query',
+      query,
+      formatted,
+    );
+  }
+
+  // Idempotency check
+  const formattedTwice = formatQuery(formatted);
+  if (formattedTwice !== formatted) {
+    throwError('Formatting is not idempotent', query, formatted);
+  }
+}
+
+function verifyFormattingOfSampleQueries() {
+  const filePath = path.join(__dirname, 'sample_queries.json');
+  const fileContent = fs.readFileSync(filePath, 'utf-8');
+  const queries: string[] = JSON.parse(fileContent) as string[];
+  queries.forEach((query) => verifyFormatting(query));
+}
+
+verifyFormattingOfSampleQueries();