Add new loader option "contextAsConfigBasePath", which when set to tr…

…ue, parses to tsconfig file with respect to webpack context path (https://webpack.js.org/configuration/entry-context/#context) instead of the location of  the config file. So all relative paths in config file are treated relative to webpack context This makes configurations possible, where the tsconfig file is located in a npm package or elsewhere in the project structure.

src/config.ts

@@ -116,12 +116,12 @@ function findConfigFile(compiler: typeof typescript, requestDirPath: string, con
 export function getConfigParseResult(
     compiler: typeof typescript,
     configFile: ConfigFile,
-    configFilePath: string
+    basePath: string
 ) {
     const configParseResult = compiler.parseJsonConfigFileContent(
         configFile.config,
         compiler.sys,
-        path.dirname(configFilePath || '')
+        basePath
     );
 
     return configParseResult;

src/index.ts

@@ -139,6 +139,7 @@ function makeLoaderOptions(instanceName: string, configFileOptions: Partial<Load
         logInfoToStdOut: false,
         compiler: 'typescript',
         configFile: 'tsconfig.json',
+        contextAsConfigBasePath: false,
         transpileOnly: false,
         compilerOptions: {},
         appendTsSuffixTo: [],

src/instances.ts

@@ -71,7 +71,11 @@ function successfulTypeScriptInstance(
 
     const { configFilePath, configFile } = configFileAndPath;
 
-    const configParseResult = getConfigParseResult(compiler, configFile, configFilePath!);
+    const basePath = loaderOptions.contextAsConfigBasePath
+        ? loader.context
+        : path.dirname(configFilePath || '');
+
+    const configParseResult = getConfigParseResult(compiler, configFile, basePath);
 
     if (configParseResult.errors.length > 0 && !loaderOptions.happyPackMode) {
         const errors = formatErrors(configParseResult.errors, loaderOptions, colors, compiler, { file: configFilePath });

src/interfaces.ts

@@ -266,6 +266,7 @@ export interface LoaderOptions {
     instance: string;
     compiler: string;
     configFile: string;
+    contextAsConfigBasePath: boolean;
     transpileOnly: boolean;
     ignoreDiagnostics: number[];
     errorFormatter: (message: ErrorInfo, colors: Chalk) => string;