warn before saving a stack whose compose path won't survive a recreate

tests/unpersisted-compose-path.test.ts

@@ -0,0 +1,113 @@
+/**
+ * #1524: warn when a custom stack compose path is not under any Dockhand container
+ * mount, so it would be written to the container's throwaway layer and lost on recreate.
+ */
+
+import { describe, test, expect } from 'bun:test';
+import { unpersistedComposePathWarning, pathOverriddenBySubMount, translateContainerPathViaMount, __setCachedMountsForTest } from '../src/lib/server/host-path';
+
+const MOUNTS = [
+	{ source: 'dockhand_data', destination: '/app/data' },
+	{ source: '/opt/stacks', destination: '/opt/stacks' },
+];
+
+describe('unpersistedComposePathWarning', () => {
+	test('warns for a path outside every mount', () => {
+		const w = unpersistedComposePathWarning('/home/docker/minecraft/compose.yaml', MOUNTS);
+		expect(w).toContain('/home/docker/minecraft/compose.yaml');
+		expect(w).toContain('recreated');
+	});
+
+	test('no warning for a path under the data volume (default location)', () => {
+		expect(unpersistedComposePathWarning('/app/data/stacks/Production/web/compose.yaml', MOUNTS)).toBeNull();
+	});
+
+	test('no warning for a path under a user-added bind mount', () => {
+		expect(unpersistedComposePathWarning('/opt/stacks/web/compose.yaml', MOUNTS)).toBeNull();
+	});
+
+	test('a path exactly equal to a mount destination is under it', () => {
+		expect(unpersistedComposePathWarning('/opt/stacks', MOUNTS)).toBeNull();
+	});
+
+	test('a prefix that is not a path boundary does NOT count as under the mount', () => {
+		// /app/database is not under /app/data even though the string starts with it.
+		expect(unpersistedComposePathWarning('/app/database/compose.yaml', MOUNTS)).not.toBeNull();
+	});
+
+	test('bare metal (no mounts) never warns', () => {
+		expect(unpersistedComposePathWarning('/home/docker/x/compose.yaml', [])).toBeNull();
+	});
+
+	test('a relative path is not guarded (resolved against DATA_DIR elsewhere)', () => {
+		expect(unpersistedComposePathWarning('compose.yaml', MOUNTS)).toBeNull();
+		expect(unpersistedComposePathWarning('./sub/compose.yaml', MOUNTS)).toBeNull();
+	});
+
+	test('null / empty path never warns', () => {
+		expect(unpersistedComposePathWarning(null, MOUNTS)).toBeNull();
+		expect(unpersistedComposePathWarning('', MOUNTS)).toBeNull();
+		expect(unpersistedComposePathWarning(undefined, MOUNTS)).toBeNull();
+	});
+});
+
+describe('pathOverriddenBySubMount (#1533)', () => {
+	// The exact #1533 topology: /app/data on a named volume, /app/data/stacks on a
+	// separate bind. A stack under /app/data/stacks lives on the bind, not the volume,
+	// so the DATA_DIR translation is wrong and must yield to the mount translation.
+	const SUBMOUNT = [
+		{ source: '/home/docker/docker/volumes/dockhand_data/_data', destination: '/app/data' },
+		{ source: '/home/docker/compose', destination: '/app/data/stacks' },
+	];
+
+	test('true when a deeper bind overrides the stack subpath', () => {
+		expect(pathOverriddenBySubMount('/app/data/stacks/adguard', '/app/data', SUBMOUNT)).toBe(true);
+	});
+
+	test('true when the path equals the sub-mount destination', () => {
+		expect(pathOverriddenBySubMount('/app/data/stacks', '/app/data', SUBMOUNT)).toBe(true);
+	});
+
+	test('false for a DATA_DIR path NOT covered by the sub-mount', () => {
+		// /app/data/db is under DATA_DIR but not under the /app/data/stacks bind.
+		expect(pathOverriddenBySubMount('/app/data/db', '/app/data', SUBMOUNT)).toBe(false);
+	});
+
+	test('false when the only mount IS DATA_DIR itself (normal single-volume setup)', () => {
+		const single = [{ source: 'dockhand_data', destination: '/app/data' }];
+		expect(pathOverriddenBySubMount('/app/data/stacks/adguard', '/app/data', single)).toBe(false);
+	});
+
+	test('false with no mounts (bare metal)', () => {
+		expect(pathOverriddenBySubMount('/app/data/stacks/adguard', '/app/data', [])).toBe(false);
+	});
+
+	test('path-boundary safe: /app/database is not under /app/data', () => {
+		const m = [{ source: '/x', destination: '/app/database' }];
+		expect(pathOverriddenBySubMount('/app/data/stacks/adguard', '/app/data', m)).toBe(false);
+	});
+
+	test('trailing slashes on DATA_DIR / destinations are normalized', () => {
+		const m = [{ source: '/home/docker/compose', destination: '/app/data/stacks/' }];
+		expect(pathOverriddenBySubMount('/app/data/stacks/adguard', '/app/data/', m)).toBe(true);
+	});
+
+	// The load-bearing invariant of the #1533 fix: when we NULL dataDirHostPath because a
+	// sub-mount overrides, mountHostPath (translateContainerPathViaMount) MUST resolve non-null
+	// - otherwise we'd regress a wrong-but-found path into a hard-fail (unknown).
+	test('overridden => translateContainerPathViaMount resolves non-null (no hard-fail regression)', () => {
+		const mounts = [
+			{ source: '/home/docker/docker/volumes/dockhand_data/_data', destination: '/app/data' },
+			{ source: '/home/docker/compose', destination: '/app/data/stacks' },
+		];
+		const path = '/app/data/stacks/adguard';
+		try {
+			__setCachedMountsForTest(mounts);
+			expect(pathOverriddenBySubMount(path, '/app/data', mounts)).toBe(true);
+			// the very folder the backup helper will bind-mount:
+			expect(translateContainerPathViaMount(path)).toBe('/home/docker/compose/adguard');
+		} finally {
+			__setCachedMountsForTest(null);
+		}
+	});
+});