feat(reporters): add built-in "json" reporter and rename "default" to "pretty"

packages/cli/src/reporters/json.ts

@@ -0,0 +1,60 @@
+import { type ReporterInitParameters, type EmigrateReporter, type MigrationMetadataFinished } from '@emigrate/types';
+import { toSerializedError } from '../errors.js';
+
+class JsonReporter implements EmigrateReporter {
+  #parameters!: ReporterInitParameters;
+  #startTime!: number;
+
+  onInit(parameters: ReporterInitParameters): void {
+    this.#startTime = Date.now();
+    this.#parameters = parameters;
+  }
+
+  onFinished(migrations: MigrationMetadataFinished[], error?: Error | undefined): void {
+    const { command, version } = this.#parameters;
+
+    let numberDoneMigrations = 0;
+    let numberSkippedMigrations = 0;
+    let numberFailedMigrations = 0;
+    let numberPendingMigrations = 0;
+
+    for (const migration of migrations) {
+      // eslint-disable-next-line unicorn/prefer-switch
+      if (migration.status === 'done') {
+        numberDoneMigrations++;
+      } else if (migration.status === 'skipped') {
+        numberSkippedMigrations++;
+      } else if (migration.status === 'failed') {
+        numberFailedMigrations++;
+      } else {
+        numberPendingMigrations++;
+      }
+    }
+
+    const result = {
+      command,
+      version,
+      numberTotalMigrations: migrations.length,
+      numberDoneMigrations,
+      numberSkippedMigrations,
+      numberFailedMigrations,
+      numberPendingMigrations,
+      success: !error,
+      startTime: this.#startTime,
+      endTime: Date.now(),
+      error: error ? toSerializedError(error) : undefined,
+      migrations: migrations.map((migration) => ({
+        name: migration.filePath,
+        status: migration.status,
+        duration: 'duration' in migration ? migration.duration : 0,
+        error: 'error' in migration ? toSerializedError(migration.error) : undefined,
+      })),
+    };
+
+    console.log(JSON.stringify(result, undefined, 2));
+  }
+}
+
+const jsonReporter = new JsonReporter() as EmigrateReporter;
+
+export default jsonReporter;