Fix: rotate resize param on multiples of 90

packages/plugin-rotate/src/index.js

@@ -231,8 +231,12 @@ export default () => ({
       return throwError.call(this, "mode must be a boolean or a string", cb);
     }
 
-    if (Math.abs(deg % 90) === 0) {
-      // apply matrixRotate if the angle is a multiple of 90 degrees (eg: 180 or -90)
+    // use matrixRotate if the angle is a multiple of 90 degrees (eg: 180 or -90) and resize is allowed or not needed.
+    const matrixRotateAllowed =
+      deg % 90 === 0 &&
+      (mode || this.bitmap.width === this.bitmap.height || deg % 180 === 0);
+
+    if (matrixRotateAllowed) {
       matrixRotate.call(this, deg);
     } else {
       advancedRotate.call(this, deg, mode, cb);

packages/plugin-rotate/test/rotation.test.js

@@ -567,3 +567,44 @@ describe("Rotate a non-square image", () => {
     );
   });
 });
+
+describe("Rotate a non-square image without resizing", () => {
+  let imgSrc = null;
+  before((done) => {
+    jimp
+      .read(mkJGD("□□□□□□□□", "▹▹▹▹▹▹▹▹", "▿▿▿▿▿▿▿▿", "□□□□□□□□"))
+      .then((imgJimp) => {
+        imgSrc = imgJimp;
+        done();
+      })
+      .catch(done);
+  });
+
+  it("90 degrees", () => {
+    expectToBeJGD(
+      imgSrc.clone().rotate(90, false).getJGDSync(),
+      mkJGD(" □▹▿□   ", " □▹▿□   ", " □▹▿□   ", " □▹▿□   ")
+    );
+  });
+
+  it("180 degrees", () => {
+    expectToBeJGD(
+      imgSrc.clone().rotate(180, false).getJGDSync(),
+      mkJGD("□□□□□□□□", "▿▿▿▿▿▿▿▿", "▹▹▹▹▹▹▹▹", "□□□□□□□□")
+    );
+  });
+
+  it("270 degrees", () => {
+    expectToBeJGD(
+      imgSrc.clone().rotate(270, false).getJGDSync(),
+      mkJGD("  □▿▹□  ", "  □▿▹□  ", "  □▿▹□  ", "  □▿▹□  ")
+    );
+  });
+
+  it("45 degrees", () => {
+    expectToBeJGD(
+      imgSrc.clone().rotate(45, false).getJGDSync(),
+      mkJGD(" □▹▹▿□□ ", "□▹▹▿□□  ", "▹▹▿□□   ", "▹▿□□    ")
+    );
+  });
+});