Pass ts.Program to getCustomTransformers()

A lot of transformers requires a Program instance so we pass ts.Program
to getCustomTransformers() to be able to pass it on to transformers

README.md

@@ -252,7 +252,7 @@ This will ensure that the plugin checks for both syntactic errors (eg `const arr
 
 Also, if you are using `thread-loader` in watch mode, remember to set `poolTimeout: Infinity` so workers don't die.
 
-#### getCustomTransformers _( () => { before?: TransformerFactory<SourceFile>[]; after?: TransformerFactory<SourceFile>[]; } )_
+#### getCustomTransformers _( (program: Program) => { before?: TransformerFactory<SourceFile>[]; after?: TransformerFactory<SourceFile>[]; } )_
 
 Provide custom transformers - only compatible with TypeScript 2.3+ (and 2.4 if using `transpileOnly` mode). For example usage take a look at [typescript-plugin-styled-components](https://github.com/Igorbek/typescript-plugin-styled-components) or our [test](test/comparison-tests/customTransformer).
 

src/instances.ts

@@ -188,7 +188,7 @@ function successfulTypeScriptInstance(
       program,
       dependencyGraph: {},
       reverseDependencyGraph: {},
-      transformers: getCustomTransformers(),
+      transformers: getCustomTransformers(program),
       colors
     };
 
@@ -235,7 +235,7 @@ function successfulTypeScriptInstance(
     otherFiles,
     languageService: null,
     version: 0,
-    transformers: getCustomTransformers(),
+    transformers: {} as typescript.CustomTransformers, // this is only set temporarily, custom transformers are created further down
     dependencyGraph: {},
     reverseDependencyGraph: {},
     modifiedFiles: null,
@@ -267,6 +267,8 @@ function successfulTypeScriptInstance(
     instance.program = instance.watchOfFilesAndCompilerOptions
       .getProgram()
       .getProgram();
+
+    instance.transformers = getCustomTransformers(instance.program);
   } else {
     const servicesHost = makeServicesHost(
       scriptRegex,

src/interfaces.ts

@@ -330,7 +330,7 @@ export interface LoaderOptions {
   happyPackMode: boolean;
   getCustomTransformers?:
     | string
-    | (() => typescript.CustomTransformers | undefined);
+    | ((program: typescript.Program) => typescript.CustomTransformers | undefined);
   experimentalWatchApi: boolean;
   allowTsInNodeModules: boolean;
   experimentalFileCaching: boolean;

test/comparison-tests/customTransformer/webpack.config.js

@@ -17,7 +17,7 @@ module.exports = {
                 test: /\.ts$/,
                 loader: 'ts-loader',
                 options: {
-                    getCustomTransformers: () => ({
+                    getCustomTransformers: (program) => ({
                         before: [uppercaseStringLiteralTransformer]
                     })
                 }

test/comparison-tests/customTransformerUsingPathString/customerTransformers.js

@@ -1,5 +1,5 @@
 var uppercaseStringLiteralTransformer = require('./uppercaseStringLiteralTransformer').default;
 
-module.exports = () => ({
+module.exports = (program) => ({
   before: [uppercaseStringLiteralTransformer]
 });