fix(runtime-generator): fix module not found errors for custom spriteModule or symbolModule

This change fixes module not found errors that could occur when specifying a custom spriteModule or
symbolModule. Previously the import statements this loader generated would only work for svg imports
made from certain directories.

Author: bimbiltu

lib/runtime-generator.js

@@ -1,3 +1,4 @@
+const { isAbsolute, join } = require('path');
 const { stringifyRequest } = require('loader-utils');
 const {
   stringify,
@@ -16,7 +17,7 @@ const {
  * @return {string}
  */
 function runtimeGenerator(params) {
-  const { symbol, config, context } = params;
+  const { symbol, config, context, loaderContext } = params;
   const { extract, esModule, spriteModule, symbolModule, runtimeCompat, publicPath } = config;
   let runtime;
 
@@ -33,8 +34,11 @@ function runtimeGenerator(params) {
     }`;
     runtime = generateExport(data, esModule);
   } else {
-    const spriteModuleImport = stringifyRequest({ context }, spriteModule);
-    const symbolModuleImport = stringifyRequest({ context }, symbolModule);
+    const spriteModuleAbsPath = isAbsolute(spriteModule) ? spriteModule : join(context, spriteModule);
+    const symbolModuleAbsPath = isAbsolute(symbolModule) ? symbolModule : join(context, symbolModule);
+
+    const spriteModuleImport = stringifyRequest(loaderContext, spriteModuleAbsPath);
+    const symbolModuleImport = stringifyRequest(loaderContext, symbolModuleAbsPath);
 
     runtime = [
       generateImport('SpriteSymbol', symbolModuleImport, esModule),