fix - Fix undefined use (#166)

Closes #165.

Author: bebraw

src/index.ts

@@ -177,14 +177,19 @@ function mergeWithRule({
           });
           break;
         case CustomizeRule.Append:
+          if (!bMatches.length) {
+            ret[k] = v;
+
+            break;
+          }
+
           const appendValue = last(bMatches)[k];
 
           if (!isArray(v) || !isArray(appendValue)) {
             throw new TypeError("Trying to append non-arrays");
           }
 
-          ret[k] =
-            bMatches.length > 0 ? (v as Array<any>).concat(appendValue) : v;
+          ret[k] = v.concat(appendValue);
           break;
         case CustomizeRule.Merge:
           const lastValue = last(bMatches)[k];
@@ -197,13 +202,19 @@ function mergeWithRule({
           ret[k] = { ...v, ...lastValue };
           break;
         case CustomizeRule.Prepend:
+          if (!bMatches.length) {
+            ret[k] = v;
+
+            break;
+          }
+
           const prependValue = last(bMatches)[k];
 
           if (!isArray(v) || !isArray(prependValue)) {
             throw new TypeError("Trying to prepend non-arrays");
           }
 
-          ret[k] = bMatches.length > 0 ? prependValue.concat(v) : v;
+          ret[k] = prependValue.concat(v);
           break;
         case CustomizeRule.Replace:
           ret[k] = bMatches.length > 0 ? last(bMatches)[k] : v;

test/merge-with-rules.test.ts

@@ -893,4 +893,154 @@ describe("Merge with rules", function () {
 
     expect(mergeRules(a, b)).toEqual(result);
   });
+
+  it("should append with local match (#165)", function () {
+    const base = {
+      module: {
+        rules: [
+          {
+            test: /\.s(a|c)ss$/,
+            use: [
+              {
+                loader: "css-loader",
+              },
+              {
+                loader: "sass-loader",
+              },
+            ],
+          },
+          {
+            test: /\.(png|jpe?g|gif|svg)$/i,
+            use: [
+              {
+                loader: "file-loader",
+              },
+            ],
+          },
+        ],
+      },
+    };
+    const development = {
+      module: {
+        rules: [
+          {
+            test: /\.s(a|c)ss$/,
+            use: ["style-loader"],
+          },
+        ],
+      },
+    };
+    const result = {
+      module: {
+        rules: [
+          {
+            test: /\.s(a|c)ss$/,
+            use: [
+              {
+                loader: "css-loader",
+              },
+              {
+                loader: "sass-loader",
+              },
+              "style-loader",
+            ],
+          },
+          {
+            test: /\.(png|jpe?g|gif|svg)$/i,
+            use: [
+              {
+                loader: "file-loader",
+              },
+            ],
+          },
+        ],
+      },
+    };
+
+    expect(
+      mergeWithRules({
+        module: {
+          rules: {
+            test: CustomizeRule.Match,
+            use: CustomizeRule.Append,
+          },
+        },
+      })(base, development)
+    ).toEqual(result);
+  });
+
+  it("should prepend with local match (#165)", function () {
+    const base = {
+      module: {
+        rules: [
+          {
+            test: /\.s(a|c)ss$/,
+            use: [
+              {
+                loader: "css-loader",
+              },
+              {
+                loader: "sass-loader",
+              },
+            ],
+          },
+          {
+            test: /\.(png|jpe?g|gif|svg)$/i,
+            use: [
+              {
+                loader: "file-loader",
+              },
+            ],
+          },
+        ],
+      },
+    };
+    const development = {
+      module: {
+        rules: [
+          {
+            test: /\.s(a|c)ss$/,
+            use: ["style-loader"],
+          },
+        ],
+      },
+    };
+    const result = {
+      module: {
+        rules: [
+          {
+            test: /\.s(a|c)ss$/,
+            use: [
+              "style-loader",
+              {
+                loader: "css-loader",
+              },
+              {
+                loader: "sass-loader",
+              },
+            ],
+          },
+          {
+            test: /\.(png|jpe?g|gif|svg)$/i,
+            use: [
+              {
+                loader: "file-loader",
+              },
+            ],
+          },
+        ],
+      },
+    };
+
+    expect(
+      mergeWithRules({
+        module: {
+          rules: {
+            test: CustomizeRule.Match,
+            use: CustomizeRule.Prepend,
+          },
+        },
+      })(base, development)
+    ).toEqual(result);
+  });
 });