generate a compose file from any container - save as new or append to existing stack

tests/compose-merge.test.ts

@@ -0,0 +1,128 @@
+/**
+ * Unit tests for the "Append to existing" merge helpers (#489): merging a generated
+ * single-service compose into an existing stack compose, and computing the highlight range
+ * of the added service. No browser needed - pure js-yaml logic.
+ *
+ * Run with: bun test tests/compose-merge.test.ts
+ */
+import { describe, test, expect } from 'bun:test';
+import yaml from 'js-yaml';
+import { mergeServiceIntoCompose, computeAddedRange } from '../src/lib/utils/compose-merge';
+
+const BASE = `services:
+  web:
+    image: nginx:latest
+    ports:
+      - '8080:80'
+`;
+
+describe('mergeServiceIntoCompose', () => {
+	test('adds a new service under services without touching the existing one', () => {
+		const service = `services:
+  redis:
+    image: redis:7
+`;
+		const { merged, key, renamed } = mergeServiceIntoCompose(BASE, service);
+		expect(key).toBe('redis');
+		expect(renamed).toBe(false);
+		const doc = yaml.load(merged) as any;
+		expect(Object.keys(doc.services).sort()).toEqual(['redis', 'web']);
+		expect(doc.services.web.image).toBe('nginx:latest');
+		expect(doc.services.redis.image).toBe('redis:7');
+	});
+
+	test('auto-suffixes on a name clash instead of overwriting', () => {
+		const service = `services:
+  web:
+    image: caddy:2
+`;
+		const { merged, key, renamed } = mergeServiceIntoCompose(BASE, service);
+		expect(key).toBe('web-2');
+		expect(renamed).toBe(true);
+		const doc = yaml.load(merged) as any;
+		// original web is untouched, the added one is web-2
+		expect(doc.services.web.image).toBe('nginx:latest');
+		expect(doc.services['web-2'].image).toBe('caddy:2');
+	});
+
+	test('picks the lowest free suffix when -2 is also taken', () => {
+		const base = `services:
+  web:
+    image: nginx:latest
+  web-2:
+    image: nginx:1.25
+`;
+		const service = `services:
+  web:
+    image: caddy:2
+`;
+		const { key } = mergeServiceIntoCompose(base, service);
+		expect(key).toBe('web-3');
+	});
+
+	test('carries over top-level networks and volumes the service references', () => {
+		const service = `services:
+  db:
+    image: postgres:16
+    networks:
+      - backend
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+networks:
+  backend:
+    external: true
+volumes:
+  pgdata:
+    external: true
+`;
+		const { merged } = mergeServiceIntoCompose(BASE, service);
+		const doc = yaml.load(merged) as any;
+		expect(doc.networks.backend).toEqual({ external: true });
+		expect(doc.volumes.pgdata).toEqual({ external: true });
+	});
+
+	test('handles an empty base compose (creates services)', () => {
+		const service = `services:
+  app:
+    image: alpine
+`;
+		const { merged, key } = mergeServiceIntoCompose('', service);
+		expect(key).toBe('app');
+		expect((yaml.load(merged) as any).services.app.image).toBe('alpine');
+	});
+});
+
+describe('computeAddedRange', () => {
+	test('returns the exact block of the added service', () => {
+		const service = `services:
+  redis:
+    image: redis:7
+`;
+		const { merged, key } = mergeServiceIntoCompose(BASE, service);
+		const [range] = computeAddedRange(merged, key);
+		const lines = merged.split('\n');
+		// the highlighted range must start at the `  redis:` line
+		expect(lines[range.line - 1]).toMatch(/^\s+redis:/);
+		// and every highlighted line must be inside the redis block (indent > 2) or the header
+		for (let l = range.line; l <= range.endLine; l++) {
+			expect(lines[l - 1].startsWith('  ')).toBe(true);
+		}
+	});
+
+	test('does NOT over-highlight the trailing blank line when the service is last', () => {
+		// merged doc ends with the added service and a trailing newline from yaml.dump.
+		const service = `services:
+  last:
+    image: busybox
+`;
+		const { merged, key } = mergeServiceIntoCompose(BASE, service);
+		const [range] = computeAddedRange(merged, key);
+		const lines = merged.split('\n');
+		// endLine must be a real content line, not the trailing empty one.
+		expect(lines[range.endLine - 1].trim()).not.toBe('');
+	});
+
+	test('returns empty when the key is absent', () => {
+		expect(computeAddedRange(BASE, 'nope')).toEqual([]);
+	});
+});