feat: support for golang

README.md

@@ -126,6 +126,45 @@ original module. This code depends on the following NuGet package (It is already
 
 The output directory will also include a tarball `[email protected]` that must be bundled in your project (It is already included as an embedded resource in the generated project).
 
+### Go Output
+
+To produce a Go module from your source, use the `golang` option:
+
+```ts
+await srcmak('srcdir', {
+  golang: {
+    outdir: '/path/to/project/root',
+    moduleName: 'github.com/yourorg/your-root-project',
+    packageName: 'helloworld'
+  }
+});
+```
+
+Or the `--golang-*` switches in the CLI:
+
+```bash
+$ jsii-srcmak /src/dir --golang-outdir=dir --golang-module="github.com/yourorg/your-root-project" --golang-package="helloworld"
+```
+
+* The `outdir`/`--golang-outdir` option points to the root directory of your base Go project (where your `go.mod` is in, if you have one).
+* The `moduleName`/`--golang-module` option must match the Go module name of the project that includes the generated source code e.g. `github.com/yourorg/your-root-project`. This is currently required, because the generated code needs to reference a submodule which is generated in a nested directory (see also upstream issue https://github.com/aws/jsii/issues/2847 for more information).
+* The `packageName`/`--golang-package` is the package in which the generated Go code will be in. It will be placed in the submodule. So the import path becomes e.g. `github.com/yourorg/your-root-project/yourpackage`.
+
+The output directory will include a directory named with the `packageName`/`--golang-package` containing the generated Go code.
+This code depends on the following Go module:
+
+- [jsii-runtime-go](github.com/aws/jsii-runtime-go)
+
+which you need to include in your `go.mod`:
+```
+require github.com/aws/jsii-runtime-go v1.29.0 # update the version to match the jsii version used in your version of jsii-srcmak
+```
+
+
+#### Nested output directories
+It is possible to set the `outdir`/`--golang-outdir` option to a directory other than the root of your base Go project. For example, if you want to nest the generated code in a folder `generated` or similar.  
+In that case you need to append the subdirectory to the module name (e.g. `github.com/yourorg/your-root-project/generated`). Your import path will then become e.g. `github.com/yourorg/your-root-project/generated/yourpackage`.
+
 ### Entrypoint
 
 The `entrypoint` option can be used to customize the name of the typescript entrypoint (default is `index.ts`).

src/cli.ts

@@ -13,6 +13,9 @@ async function main() {
     .option('java-package', { desc: 'the java package (namespace) to use for all generated types', type: 'string' })
     .option('csharp-outdir', { desc: 'C# output directory (requires --csharp-namespace)', type: 'string' })
     .option('csharp-namespace', { desc: 'the C# namespace to use for all generated types', type: 'string' })
+    .option('golang-outdir', { desc: 'golang output directory (requires --golang-module)', type: 'string' })
+    .option('golang-module', { desc: 'the golang module to use for all generated types', type: 'string' })
+    .option('golang-package', { desc: 'the golang package name to use for all generated types', type: 'string' })
     .showHelpOnFail(true)
     .help();
 
@@ -33,6 +36,7 @@ async function main() {
     ...parsePythonOptions(),
     ...parseJavaOptions(),
     ...parseCSharpOptions(),
+    ...parseGoLangOptions(),
   });
 
   function parseJsiiOptions() {
@@ -87,6 +91,23 @@ async function main() {
     };
   }
 
+  function parseGoLangOptions() {
+    const outdir = argv['golang-outdir'];
+    const module = argv['golang-module'];
+    const packageName = argv['golang-package'];
+    if (!outdir && !module) { return undefined; }
+    if (!outdir) { throw new Error('--golang-outdir is required'); }
+    if (!module) { throw new Error('--golang-module is required'); }
+    if (!packageName) { throw new Error('--golang-package is required'); }
+    return {
+      golang: {
+        outdir: outdir,
+        moduleName: module,
+        packageName: packageName,
+      },
+    };
+  }
+
   function parseDepOption() {
     if (argv.dep?.length === 0) { return undefined; }
     return {

src/compile.ts

@@ -91,6 +91,13 @@ export async function compile(workdir: string, options: Options) {
     };
   }
 
+  if (options.golang) {
+    targets.go = {
+      moduleName: options.golang.moduleName,
+      packageName: options.golang.packageName,
+    };
+  }
+
   await fs.writeFile(path.join(workdir, 'package.json'), JSON.stringify(pkg, undefined, 2));
 
   await exec(compilerModule, args, {

src/options.ts

@@ -46,6 +46,13 @@ export interface Options {
    * @default - C# is not generated
    */
   csharp?: CSharpOutputOptions;
+
+  /**
+   * Produces Golang code.
+   *
+   * @default - go is not generated
+   */
+  golang?: GoLangOutputOptions;
 }
 
 export interface JsiiOutputOptions {
@@ -99,3 +106,29 @@ export interface CSharpOutputOptions {
    */
   namespace: string;
 }
+
+export interface GoLangOutputOptions {
+  /**
+   * Base root directory.
+   */
+  outdir: string;
+
+  /**
+   * The go module name
+   *
+   * This must match the name of the parent go module the source code is generated in (e.g. github.com/yourorg/yourproject).
+   * See https://github.com/aws/jsii/issues/2847#issue-896419111 for the background on why this is required.
+   *
+   * This must follow standard Go module name conventions.
+   * For example, it cannot include an underscore ('_') or be camelCased
+   */
+  moduleName: string;
+
+  /**
+   * The name of the Go package.
+   *
+   * E.g. "tools" would result in something like github.com/yourorg/yourproject/tools
+   * depeding on the supplied moduleName
+   */
+  packageName: string;
+}

src/srcmak.ts

@@ -51,5 +51,15 @@ export async function srcmak(srcdir: string, options: Options = { }) {
       const target = path.join(options.csharp.outdir, reldir);
       await fs.move(source, target, { overwrite: true });
     }
+
+    if (options.golang) {
+      const reldir = options.golang.packageName;
+      const source = path.resolve(path.join(workdir, 'dist/go/', reldir));
+      const target = path.join(options.golang.outdir, reldir);
+      await fs.move(source, target, { overwrite: true });
+      // remove go.mod as this would make it a submodule
+      // awaits https://github.com/aws/jsii/issues/2848
+      await fs.remove(path.join(target, 'go.mod'));
+    }
   });
 }

src/util.ts

@@ -75,4 +75,8 @@ export function validateOptions(options: Options) {
   if (options.csharp?.namespace.includes('-')) {
     throw new Error(`C# namespace [${options.csharp.namespace}] may not contain "-"`);
   }
+
+  if (options.golang?.moduleName.includes('_')) {
+    throw new Error(`Go module name [${options.golang.moduleName}] may not contain "_"`);
+  }
 }