feat: Throw if trying to merge non-objects

survivejs · Dec 12, 2020 · 157b9a0 · 157b9a0
1 parent 8a7d155
commit 157b9a0
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Showing 3 changed files with 58 additions and 3 deletions.
diff --git a/src/index.ts b/src/index.ts
@@ -183,8 +183,14 @@ function mergeWithRule({
               : v;
           break;
         case CustomizeRule.Merge:
-          // @ts-ignore: The assumption here is that both are objects
-          ret[k] = { ...v, ...last(bMatches)[k] };
+          const lastValue = last(bMatches)[k];
+
+          if (!isPlainObject(v) || !isPlainObject(lastValue)) {
+            throw new TypeError("Trying to merge non-objects");
+          }
+
+          // @ts-ignore: These should be objects now
+          ret[k] = { ...v, ...lastValue };
           break;
         case CustomizeRule.Prepend:
           ret[k] = bMatches.length > 0 ? last(bMatches)[k].concat(v) : v;

diff --git a/src/utils.ts b/src/utils.ts
@@ -10,7 +10,7 @@ function isFunction(functionToCheck) {
 }
 
 function isPlainObject(a) {
-  if (a === null) {
+  if (a === null || Array.isArray(a)) {
     return false;
   }
 

diff --git a/test/merge-with-rules.test.ts b/test/merge-with-rules.test.ts
@@ -674,6 +674,55 @@ describe("Merge with rules", function () {
     expect(_mergeWithExplicitRule(a, b)).toEqual(result);
   });
 
+  it("should throw if trying to merge non-objects", function () {
+    const _mergeWithExplicitRule = mergeWithRules({
+      module: {
+        rules: {
+          test: CustomizeRule.Match,
+          use: {
+            loader: CustomizeRule.Match,
+            options: CustomizeRule.Merge,
+          },
+        },
+      },
+    });
+    const a = {
+      resolve: { extensions: [".js"] },
+      module: {
+        rules: [
+          {
+            test: /\.css$/,
+            use: [
+              { loader: "style-loader", options: [] },
+              { loader: "sass-loader" },
+            ],
+          },
+        ],
+      },
+    };
+    const b = {
+      resolve: { extensions: [".css"] },
+      module: {
+        rules: [
+          {
+            test: /\.css$/,
+            use: [
+              {
+                loader: "style-loader",
+                options: [],
+              },
+            ],
+          },
+        ],
+      },
+    };
+
+    assert.throws(() => _mergeWithExplicitRule(a, b), {
+      name: "TypeError",
+      message: "Trying to merge non-objects",
+    });
+  });
+
   it("should work with multi-level match (#153)", function () {
     const a = {
       module: {