test(generate): add unit tests for service and timer generation

- Introduces tests to validate service and timer unit generation
- Covers description, dependencies, environment variables, and logging
- Ensures generated units meet expected configurations

src/templates/unit-generator.ts

@@ -0,0 +1,63 @@
+import { TimerOptions } from '../types/mod.ts';
+import { deriveNameFromExec, writeUnitFiles } from '../utils/mod.ts';
+
+export async function generateUnitFiles(options: TimerOptions): Promise<void> {
+    const name = options.name || deriveNameFromExec(options.exec);
+
+    const { serviceUnit, timerUnit } = generateUnits(name, options);
+
+    if (options.dryRun) {
+        console.log(`===== ${name}.service =====`);
+        console.log(serviceUnit);
+        console.log(`\n===== ${name}.timer =====`);
+        console.log(timerUnit);
+    } else {
+        const { servicePath, timerPath } = await writeUnitFiles(
+            name,
+            serviceUnit,
+            timerUnit,
+            options,
+        );
+        console.log(`Service unit written to: ${servicePath}`);
+        console.log(`Timer unit written to: ${timerPath}`);
+    }
+}
+
+export function generateUnits(name: string, options: TimerOptions): {
+    serviceUnit: string;
+    timerUnit: string;
+} {
+    const unitParts = [
+        `[Unit]`,
+        `Description=${options.description ?? name}`,
+        ...(options.after?.map((a) => `After=${a}`) ?? []),
+        ``,
+        `[Service]`,
+        `Type=oneshot`,
+        `ExecStart=${options.exec}`,
+        ...(options.environment?.map((e) => `Environment=${e}`) ?? []),
+    ];
+
+    if (options.logfile) {
+        unitParts.push(`StandardOutput=append:${options.logfile}`);
+        unitParts.push(`StandardError=append:${options.logfile}`);
+    }
+
+    const serviceUnit = unitParts.join('\n');
+
+    const timerParts = [
+        `[Unit]`,
+        `Description=Timer for ${name}`,
+        ``,
+        `[Timer]`,
+        `OnCalendar=${options.calendar}`,
+        `Persistent=true`,
+        ``,
+        `[Install]`,
+        `WantedBy=timers.target`,
+    ];
+
+    const timerUnit = timerParts.join('\n');
+
+    return { serviceUnit, timerUnit };
+}