feat: Add .fern.metadata.json to generated SDK outputs

packages/cli/generation/local-generation/local-workspace-runner/package.json

@@ -63,12 +63,14 @@
     "@fern-fern/generator-exec-sdk": "^0.0.1167",
     "chalk": "^5.3.0",
     "decompress": "^4.2.1",
+    "js-yaml": "^4.1.0",
     "prettier2": "npm:prettier@^2.7.1",
     "tmp-promise": "^3.0.3"
   },
   "devDependencies": {
     "@fern-api/configs": "workspace:*",
     "@types/decompress": "^4.2.7",
+    "@types/js-yaml": "^4.0.5",
     "@types/node": "18.15.3",
     "@types/prettier2": "npm:@types/prettier@^2.7.3",
     "depcheck": "^1.4.7",

packages/cli/generation/local-generation/local-workspace-runner/src/runGenerator.ts

@@ -204,6 +204,12 @@ export async function writeFilesToDiskAndRunGenerator({
         runner
     });
 
+    await writeFernMetadata({
+        outputDirectory: absolutePathToTmpOutputDirectory,
+        generatorInvocation,
+        context
+    });
+
     const taskHandler = new LocalTaskHandler({
         context,
         absolutePathToLocalOutput,
@@ -264,3 +270,41 @@ function getSourceConfig(workspace: FernWorkspace): SourceConfig {
 function getDockerDestinationForSource(source: IdentifiableSource): string {
     return `${DOCKER_SOURCES_DIRECTORY}/${source.id}`;
 }
+
+function getCliVersion(): string {
+    return process.env.CLI_VERSION ?? "unknown";
+}
+
+interface FernMetadata {
+    cliVersion: string;
+    generatorName: string;
+    generatorVersion: string;
+    generatorsYml?: {
+        config?: unknown;
+    };
+}
+
+async function writeFernMetadata({
+    outputDirectory,
+    generatorInvocation,
+    context
+}: {
+    outputDirectory: AbsoluteFilePath;
+    generatorInvocation: generatorsYml.GeneratorInvocation;
+    context: TaskContext;
+}): Promise<void> {
+    const cliVersion = getCliVersion();
+
+    const metadata: FernMetadata = {
+        cliVersion,
+        generatorName: generatorInvocation.name,
+        generatorVersion: generatorInvocation.version,
+        generatorsYml: {
+            config: generatorInvocation.config
+        }
+    };
+
+    const metadataPath = join(outputDirectory, ".fern.metadata.json");
+    await writeFile(metadataPath, JSON.stringify(metadata, null, 2));
+    context.logger.debug(`Wrote Fern metadata to: ${metadataPath}`);
+}

packages/cli/generation/remote-generation/remote-workspace-runner/src/RemoteTaskHandler.ts

@@ -8,7 +8,7 @@ import axios from "axios";
 import chalk from "chalk";
 import decompress from "decompress";
 import { createWriteStream } from "fs";
-import { mkdir, rm } from "fs/promises";
+import { mkdir, rm, writeFile } from "fs/promises";
 import path from "path";
 import { pipeline } from "stream/promises";
 import terminalLink from "terminal-link";
@@ -101,7 +101,8 @@ export class RemoteTaskHandler {
                         await downloadFilesForTask({
                             s3PreSignedReadUrl: finishedStatus.s3PreSignedReadUrlV2,
                             absolutePathToLocalOutput,
-                            context: this.context
+                            context: this.context,
+                            generatorInvocation: this.generatorInvocation
                         });
                     }
                 }
@@ -152,18 +153,26 @@ export class RemoteTaskHandler {
 async function downloadFilesForTask({
     s3PreSignedReadUrl,
     absolutePathToLocalOutput,
-    context
+    context,
+    generatorInvocation
 }: {
     s3PreSignedReadUrl: string;
     absolutePathToLocalOutput: AbsoluteFilePath;
     context: InteractiveTaskContext;
+    generatorInvocation: generatorsYml.GeneratorInvocation;
 }) {
     try {
         await downloadZipForTask({
             s3PreSignedReadUrl,
             absolutePathToLocalOutput
         });
 
+        await writeFernMetadata({
+            outputDirectory: absolutePathToLocalOutput,
+            generatorInvocation,
+            context
+        });
+
         context.logger.info(chalk.green(`Downloaded to ${absolutePathToLocalOutput}`));
     } catch (e) {
         context.failAndThrow("Failed to download files", e);
@@ -209,3 +218,41 @@ function convertLogLevel(logLevel: FernFiddle.LogLevel): LogLevel {
             return LogLevel.Info;
     }
 }
+
+function getCliVersion(): string {
+    return process.env.CLI_VERSION ?? "unknown";
+}
+
+interface FernMetadata {
+    cliVersion: string;
+    generatorName: string;
+    generatorVersion: string;
+    generatorsYml?: {
+        config?: unknown;
+    };
+}
+
+async function writeFernMetadata({
+    outputDirectory,
+    generatorInvocation,
+    context
+}: {
+    outputDirectory: AbsoluteFilePath;
+    generatorInvocation: generatorsYml.GeneratorInvocation;
+    context: InteractiveTaskContext;
+}): Promise<void> {
+    const cliVersion = getCliVersion();
+
+    const metadata: FernMetadata = {
+        cliVersion,
+        generatorName: generatorInvocation.name,
+        generatorVersion: generatorInvocation.version,
+        generatorsYml: {
+            config: generatorInvocation.config
+        }
+    };
+
+    const metadataPath = join(outputDirectory, RelativeFilePath.of(".fern.metadata.json"));
+    await writeFile(metadataPath, JSON.stringify(metadata, null, 2));
+    context.logger.debug(`Wrote Fern metadata to: ${metadataPath}`);
+}