(fix/optim): only emit type declarations once

- every other emission is just a duplicate -- no need to spend compute
  to duplicate

- this also fixes a bug with multi-entry where if an entry in a subdir
  of src/ were added, e.g. src/foo/bar, the entire tree of type
  declarations would get output into dist/foo/src/*.d.ts
  - alternatively, could call `moveTypes()` with an arg for each entry,
    but there's no need since all declarations get produced the first
    time around anyway

src/createBuildConfigs.ts

@@ -35,9 +35,9 @@ export async function createBuildConfigs(
   );
 
   return await Promise.all(
-    allInputs.map(async (options: TsdxOptions) => {
+    allInputs.map(async (options: TsdxOptions, index: number) => {
       // pass the full rollup config to tsdx.config.js override
-      const config = await createRollupConfig(options);
+      const config = await createRollupConfig(options, index);
       return tsdxConfig.rollup(config, options);
     })
   );

src/createRollupConfig.ts

@@ -23,7 +23,8 @@ const errorCodeOpts = {
 let shebang: any = {};
 
 export async function createRollupConfig(
-  opts: TsdxOptions
+  opts: TsdxOptions,
+  outputNum: number
 ): Promise<RollupOptions> {
   const findAndRecordErrorCodes = await extractErrors({
     ...errorCodeOpts,
@@ -162,6 +163,8 @@ export async function createRollupConfig(
           compilerOptions: {
             // TS -> esnext, then leave the rest to babel-preset-env
             target: 'esnext',
+            // only output declarations once
+            declaration: outputNum !== 0 ? false : undefined,
           },
         },
         check: !opts.transpileOnly,

src/index.ts

@@ -456,14 +456,14 @@ prog
           async (inputOptions: RollupOptions & { output: OutputOptions }) => {
             let bundle = await rollup(inputOptions);
             await bundle.write(inputOptions.output);
-            await deprecated.moveTypes();
           }
         )
         .catch((e: any) => {
           throw e;
         });
       logger(promise, 'Building modules');
       await promise;
+      await deprecated.moveTypes();
     } catch (error) {
       logError(error);
       process.exit(1);