(fix): parse tsconfig extends, trailing commas, and comments

- use ts.readConfigFile to properly parse a tsconfig instead of just
  trying to readJSON

src/createRollupConfig.ts

@@ -10,10 +10,11 @@ import replace from '@rollup/plugin-replace';
 import resolve from '@rollup/plugin-node-resolve';
 import sourceMaps from 'rollup-plugin-sourcemaps';
 import typescript from 'rollup-plugin-typescript2';
+import ts from 'typescript';
+
 import { extractErrors } from './errors/extractErrors';
 import { babelPluginTsdx } from './babelPluginTsdx';
 import { TsdxOptions } from './types';
-import * as fs from 'fs-extra';
 
 const errorCodeOpts = {
   errorMapFilePath: paths.appErrorsJson,
@@ -45,8 +46,12 @@ export async function createRollupConfig(
 
   let tsconfigJSON;
   try {
-    tsconfigJSON = await fs.readJSON(opts.tsconfig || paths.tsconfigJson);
-  } catch (e) {}
+    const tsconfigPath = opts.tsconfig || paths.tsconfigJson;
+    // borrowed from https://github.com/facebook/create-react-app/pull/7248
+    tsconfigJSON = ts.readConfigFile(tsconfigPath, ts.sys.readFile).config;
+  } catch (e) {
+    console.error(e);
+  }
 
   return {
     // Tell Rollup the entry point to the package
@@ -136,7 +141,7 @@ export async function createRollupConfig(
         },
       },
       typescript({
-        typescript: require('typescript'),
+        typescript: ts,
         cacheRoot: `./node_modules/.cache/tsdx/${opts.format}/`,
         tsconfig: opts.tsconfig,
         tsconfigDefaults: {

test/fixtures/build-default/tsconfig.json

@@ -25,5 +25,5 @@
     "jsx": "react",
     "esModuleInterop": true
   },
-  "include": ["src", "types"]
+  "include": ["src", "types"], // test parsing of trailing comma & comment
 }