fix(rust): read a single-quoted Cargo edition too

src/core-open/scanners/rust-scanner.ts

@@ -508,8 +508,8 @@ function parseCargoToml(
  *   edition = "2021"
  */
 function extractRustEdition(content: string): string | undefined {
-  const match = content.match(/^\s*edition\s*=\s*"(\d+)"/m);
-  return match?.[1];
+  const match = content.match(/^\s*edition\s*=\s*(["'])(\d+)\1/m);
+  return match?.[2];
 }
 
 // ── Rust project file names ──

test/cargo-rust-edition.test.ts

@@ -0,0 +1,51 @@
+/**
+ * Cargo.toml package edition. TOML basic ("2021") and literal ('2021')
+ * strings are both valid; the scanner must report the same edition and lag
+ * for either quote style.
+ */
+import * as fs from 'node:fs';
+import * as os from 'node:os';
+import * as path from 'node:path';
+import { describe, expect, it } from 'vitest';
+import { CargoCache } from '../src/core-open/scanners/cargo-cache.js';
+import { scanRustProjects } from '../src/core-open/scanners/rust-scanner.js';
+import { Semaphore } from '../src/core-open/utils/semaphore.js';
+import type { ProjectScan } from '../src/core-open/types.js';
+
+async function scanEdition(editionLine: string): Promise<ProjectScan> {
+  const root = fs.mkdtempSync(path.join(os.tmpdir(), 'vg-cargo-edition-'));
+  try {
+    fs.writeFileSync(
+      path.join(root, 'Cargo.toml'),
+      `[package]\nname = "app"\nversion = "0.1.0"\n${editionLine}\n`,
+    );
+    const projects = await scanRustProjects(root, new CargoCache(new Semaphore(1), undefined, true));
+    expect(projects).toHaveLength(1);
+    return projects[0]!;
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+}
+
+describe('Cargo package edition', () => {
+  it('reads a double-quoted edition', async () => {
+    const project = await scanEdition('edition = "2021"');
+
+    expect(project.runtime).toBe('2021');
+    expect(project.runtimeLatest).toBe('2024');
+    expect(project.runtimeMajorsBehind).toBe(1);
+  });
+
+  it('reads a single-quoted edition with the same lag as the double-quoted form', async () => {
+    const project = await scanEdition("edition = '2021'");
+
+    expect(project.runtime).toBe('2021');
+    expect(project.runtimeLatest).toBe('2024');
+    expect(project.runtimeMajorsBehind).toBe(1);
+  });
+
+  it('ignores a quoted edition that is not a year of digits', async () => {
+    expect((await scanEdition("edition = 'latest'")).runtime).toBeUndefined();
+    expect((await scanEdition('edition = "latest"')).runtime).toBeUndefined();
+  });
+});