populate environment variables again finds the repo env file

tests/preview-env-envpath.test.ts

@@ -0,0 +1,47 @@
+/**
+ * #1495 - "Populate environment variables" found no .env because the preview clone
+ * computed the base .env path by re-joining the temp dir onto an already-absolute
+ * compose path, doubling the prefix:
+ *   join(tempDir, dirname(safeComposePath), '.env')
+ *     -> /tmp/preview-x/tmp/preview-x/stacks/repro/.env   (cannot exist -> 0 vars)
+ *
+ * This calls the REAL production helper repoBaseEnvPath (the exact code previewRepoEnvFiles
+ * uses), so a revert to the buggy join fails these tests - unlike a re-implemented formula,
+ * which would stay green.
+ */
+import { describe, expect, test } from 'bun:test';
+import { sep } from 'node:path';
+import { repoBaseEnvPath } from '../src/lib/server/git-url-safety';
+
+describe('#1495 preview base .env path is not doubled', () => {
+	const tempDir = '/app/data/git-repos/preview-1788100341098-d7vddc';
+
+	test('relative compose path -> .env beside it, single temp prefix', () => {
+		const p = repoBaseEnvPath(tempDir, 'stacks/repro/docker-compose.yml');
+		expect(p).toBe(`${tempDir}/stacks/repro/.env`);
+		// the temp dir must appear exactly once (the regression put it in twice)
+		expect(p.split(tempDir).length - 1).toBe(1);
+		expect(p.startsWith(tempDir + sep)).toBe(true);
+	});
+
+	test('leading-slash compose path is treated repo-root-relative, still single prefix', () => {
+		const p = repoBaseEnvPath(tempDir, '/stacks/repro/docker-compose.yml');
+		expect(p).toBe(`${tempDir}/stacks/repro/.env`);
+		expect(p.split(tempDir).length - 1).toBe(1);
+	});
+
+	test('./ compose path resolves the same', () => {
+		const p = repoBaseEnvPath(tempDir, './stacks/repro/compose.yaml');
+		expect(p).toBe(`${tempDir}/stacks/repro/.env`);
+		expect(p.split(tempDir).length - 1).toBe(1);
+	});
+
+	test('compose at repo root -> .env at repo root', () => {
+		const p = repoBaseEnvPath(tempDir, 'docker-compose.yml');
+		expect(p).toBe(`${tempDir}/.env`);
+	});
+
+	test('a traversing compose path is still rejected (containment guard preserved)', () => {
+		expect(() => repoBaseEnvPath(tempDir, '../../etc/docker-compose.yml')).toThrow();
+	});
+});