feat: allow esbuild outExtension to be set from cli and in defineConfig

Author: Inqnuam

src/cli.ts

@@ -167,7 +167,12 @@ const options: Record<string, ICliOptions> = {
   },
   "esbuild-format": {
     type: "string",
-    description: "Sets esbuild format (cjs|esm)",
+    description: "Set esbuild format (cjs|esm)",
+  },
+  "esbuild-out-ext": {
+    type: "string",
+    description: "Set esbuild outExtension",
+    example: "aws-lambda --esbuild-out-ext .mjs --esbuild-format esm",
   },
   help: { type: "boolean", short: "h" },
 };
@@ -179,6 +184,7 @@ const { values } = parseArgs({
 
 const { port, config, debug, help, runtime, definitions, timeout, functions, handlerName, exclude, env } = values;
 const esbuildFormat = values["esbuild-format"];
+const esbuildOutExtension = values["esbuild-out-ext"];
 
 if (help) {
   printHelpAndExit();
@@ -191,10 +197,18 @@ if (definitions && functions) {
 // @ts-ignore
 const functionDefs = functions ? await getFromGlob(new RegExp(exclude), handlerName, functions as string[]) : await getFunctionsDefinitionFromFile(definitions as string);
 
-let esbuildOptions;
+let esbuildOptions = esbuildFormat || esbuildOutExtension ? {} : undefined;
 
 if (typeof esbuildFormat == "string") {
-  esbuildOptions = { format: esbuildFormat };
+  // @ts-ignore
+  esbuildOptions.format = esbuildFormat;
+}
+
+if (typeof esbuildOutExtension == "string") {
+  // @ts-ignore
+  esbuildOptions.outExtension = {
+    ".js": esbuildOutExtension,
+  };
 }
 
 run({

src/config.ts

@@ -14,7 +14,7 @@ export interface OfflineConfig {
 }
 
 export interface Config {
-  esbuild?: Omit<BuildOptions, "outExtension" | "outfile" | "bundle" | "splitting" | "stdin" | "platforme" | "metafile" | "format"> & { format?: "cjs" | "esm" };
+  esbuild?: Omit<BuildOptions, "outfile" | "bundle" | "splitting" | "stdin" | "platforme" | "metafile" | "format"> & { format?: "cjs" | "esm" };
   shimRequire?: boolean;
   includeAwsSdk?: boolean;
   server?: OfflineConfig;

src/lib/esbuild/mergeEsbuildConfig.ts

@@ -24,6 +24,10 @@ export const mergeEsbuildConfig = (esBuildConfig: BuildOptions, customEsBuildCon
     esBuildConfig.format = customEsBuildConfig.format;
   }
 
+  if (typeof customEsBuildConfig.outExtension) {
+    esBuildConfig.outExtension = customEsBuildConfig.outExtension;
+  }
+
   if ("sourcesContent" in customEsBuildConfig) {
     esBuildConfig.sourcesContent = customEsBuildConfig.sourcesContent;
   }

src/lib/esbuild/parseCustomEsbuild.ts

@@ -22,6 +22,10 @@ export const parseCustomEsbuild = (customConfig: BuildOptions) => {
     customEsBuild.format = customConfig.format;
   }
 
+  if (typeof customConfig.outExtension) {
+    customEsBuild.outExtension = customConfig.outExtension;
+  }
+
   if ("sourcesContent" in customConfig) {
     customEsBuild.sourcesContent = customConfig.sourcesContent;
   }