fix: crash when publicPath is function

src/loader.js

@@ -204,13 +204,22 @@ export function pitch(request) {
       return;
     }
 
-    const isAbsolutePublicPath = /^[a-zA-Z][a-zA-Z\d+\-.]*?:/.test(publicPath);
-    const publicPathForExtract = isAbsolutePublicPath
-      ? publicPath
-      : `${ABSOLUTE_PUBLIC_PATH}${publicPath.replace(
-          /\./g,
-          SINGLE_DOT_PATH_SEGMENT
-        )}`;
+    let publicPathForExtract;
+
+    if (typeof publicPath === "string") {
+      const isAbsolutePublicPath = /^[a-zA-Z][a-zA-Z\d+\-.]*?:/.test(
+        publicPath
+      );
+
+      publicPathForExtract = isAbsolutePublicPath
+        ? publicPath
+        : `${ABSOLUTE_PUBLIC_PATH}${publicPath.replace(
+            /\./g,
+            SINGLE_DOT_PATH_SEGMENT
+          )}`;
+    } else {
+      publicPathForExtract = publicPath;
+    }
 
     this.importModule(
       `${this.resourcePath}.webpack[javascript/auto]!=!!!${request}`,

test/cases/publicpath-function-2/expected/webpack-5-importModule/nested/again/style.css

@@ -0,0 +1,5 @@
+body {
+  background: green;
+  background-image: url(http://example.com/XXXX/c9e192c015437a21dea1.svg);
+}
+

test/cases/publicpath-function-2/expected/webpack-5-importModule/nested/style.css

@@ -0,0 +1,5 @@
+body {
+  background: red;
+  background-image: url(http://example.com/XXXX/c9e192c015437a21dea1.svg);
+}
+

test/cases/publicpath-function-2/expected/webpack-5/nested/again/style.css

@@ -0,0 +1,5 @@
+body {
+  background: green;
+  background-image: url(http://example.com/4d869bb95ecdf3f870fb/c9e192c015437a21dea1.svg);
+}
+

test/cases/publicpath-function-2/expected/webpack-5/nested/style.css

@@ -0,0 +1,5 @@
+body {
+  background: red;
+  background-image: url(http://example.com/ca6e489a6807af3e778c/c9e192c015437a21dea1.svg);
+}
+

test/cases/publicpath-function-2/nested/again/style.css

@@ -0,0 +1,4 @@
+body {
+  background: green;
+  background-image: url(../../react.svg);
+}

test/cases/publicpath-function-2/nested/style.css

@@ -0,0 +1,4 @@
+body {
+  background: red;
+  background-image: url(../react.svg);
+}

test/cases/publicpath-function-2/webpack.config.js

@@ -0,0 +1,32 @@
+import Self from "../../../src";
+
+module.exports = {
+  entry: {
+    // Specific CSS entry point, with output to a nested folder
+    "nested/style": "./nested/style.css",
+    // Note that relative nesting of output is the same as that of the input
+    "nested/again/style": "./nested/again/style.css",
+  },
+  output: {
+    // Compute publicPath relative to the CSS output
+    publicPath: (pathData) => `http://example.com/${pathData.hash}/`,
+  },
+  module: {
+    rules: [
+      {
+        test: /\.css$/,
+        use: [
+          {
+            loader: Self.loader,
+          },
+          "css-loader",
+        ],
+      },
+    ],
+  },
+  plugins: [
+    new Self({
+      filename: "[name].css",
+    }),
+  ],
+};