adds baseUrl to web_modules imports

src/commands/build.ts

@@ -315,7 +315,8 @@ export async function command(commandOptions: CommandOptions) {
               return spec;
             }
             if (dependencyImportMap.imports[spec]) {
-              let resolvedImport = path.posix.resolve(
+              let resolvedImport = path.posix.join(
+                config.buildOptions.baseUrl,
                 `/web_modules`,
                 dependencyImportMap.imports[spec],
               );
@@ -336,7 +337,7 @@ export async function command(commandOptions: CommandOptions) {
                 pkgName: missingPackageName,
               },
             });
-            return `/web_modules/${spec}.js`;
+            return path.posix.join(config.buildOptions.baseUrl, `/web_modules`, `${spec}.js`);
           });
           code = wrapImportMeta({code, env: true, hmr: false, config});
         }

test/build/base-url/.gitignore

@@ -1,2 +1 @@
 build
-node_modules

test/build/base-url/index.test.js

@@ -15,4 +15,9 @@ it('buildOptions.baseUrl', () => {
   expect(iconMatch).toBe('/static/favicon.ico');
   expect(cssMatch).toBe('/static/index.css');
   expect(jsMatch).toBe('/static/_dist_/index.js');
+
+  // web_modules imports should be rewritten to add baseUrl
+  const outputJS = fs.readFileSync(path.resolve(__dirname, 'build', '_dist_', 'index.js'), 'utf8');
+
+  expect(outputJS).toContain('/static/web_modules/array-flatten.js');
 });