Expose libvips centre option, mimics *magick +0.5px convention

test/unit/resize.js

@@ -51,137 +51,110 @@ describe('Resize dimensions', function () {
   });
 
   it('Upscale', function (done) {
-    sharp(fixtures.inputJpg).resize(3000).toBuffer(function (err, data, info) {
-      if (err) throw err;
-      assert.strictEqual(true, data.length > 0);
-      assert.strictEqual('jpeg', info.format);
-      assert.strictEqual(3000, info.width);
-      assert.strictEqual(2450, info.height);
-      done();
+    sharp(fixtures.inputJpg)
+      .resize(3000)
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(3000, info.width);
+        assert.strictEqual(2450, info.height);
+        done();
+      });
+  });
+
+  it('Invalid width - NaN', function () {
+    assert.throws(function () {
+      sharp().resize('spoons', 240);
     });
   });
 
-  it('Invalid width - NaN', function (done) {
-    let isValid = true;
-    try {
-      sharp(fixtures.inputJpg).resize('spoons', 240);
-    } catch (err) {
-      isValid = false;
-    }
-    assert.strictEqual(false, isValid);
-    done();
-  });
-
-  it('Invalid height - NaN', function (done) {
-    let isValid = true;
-    try {
-      sharp(fixtures.inputJpg).resize(320, 'spoons');
-    } catch (err) {
-      isValid = false;
-    }
-    assert.strictEqual(false, isValid);
-    done();
-  });
-
-  it('Invalid width - float', function (done) {
-    let isValid = true;
-    try {
-      sharp(fixtures.inputJpg).resize(1.5, 240);
-    } catch (err) {
-      isValid = false;
-    }
-    assert.strictEqual(false, isValid);
-    done();
-  });
-
-  it('Invalid height - float', function (done) {
-    let isValid = true;
-    try {
-      sharp(fixtures.inputJpg).resize(320, 1.5);
-    } catch (err) {
-      isValid = false;
-    }
-    assert.strictEqual(false, isValid);
-    done();
-  });
-
-  it('Invalid width - too large', function (done) {
-    let isValid = true;
-    try {
-      sharp(fixtures.inputJpg).resize(0x4000, 240);
-    } catch (err) {
-      isValid = false;
-    }
-    assert.strictEqual(false, isValid);
-    done();
-  });
-
-  it('Invalid height - too large', function (done) {
-    let isValid = true;
-    try {
-      sharp(fixtures.inputJpg).resize(320, 0x4000);
-    } catch (err) {
-      isValid = false;
-    }
-    assert.strictEqual(false, isValid);
-    done();
-  });
-
-  if (sharp.format.webp.output.buffer) {
-    it('WebP shrink-on-load rounds to zero, ensure recalculation is correct', function (done) {
-      sharp(fixtures.inputJpg)
-        .resize(1080, 607)
-        .webp()
-        .toBuffer(function (err, data, info) {
-          if (err) throw err;
-          assert.strictEqual('webp', info.format);
-          assert.strictEqual(1080, info.width);
-          assert.strictEqual(607, info.height);
-          sharp(data)
-            .resize(233, 131)
-            .toBuffer(function (err, data, info) {
-              if (err) throw err;
-              assert.strictEqual('webp', info.format);
-              assert.strictEqual(233, info.width);
-              assert.strictEqual(131, info.height);
-              done();
-            });
-        });
+  it('Invalid height - NaN', function () {
+    assert.throws(function () {
+      sharp().resize(320, 'spoons');
     });
-  }
+  });
 
-  if (sharp.format.tiff.input.file) {
-    it('TIFF embed known to cause rounding errors', function (done) {
-      sharp(fixtures.inputTiff)
-        .resize(240, 320)
-        .embed()
-        .jpeg()
-        .toBuffer(function (err, data, info) {
-          if (err) throw err;
-          assert.strictEqual(true, data.length > 0);
-          assert.strictEqual('jpeg', info.format);
-          assert.strictEqual(240, info.width);
-          assert.strictEqual(320, info.height);
-          done();
-        });
+  it('Invalid width - float', function () {
+    assert.throws(function () {
+      sharp().resize(1.5, 240);
     });
+  });
 
-    it('TIFF known to cause rounding errors', function (done) {
-      sharp(fixtures.inputTiff)
-        .resize(240, 320)
-        .jpeg()
-        .toBuffer(function (err, data, info) {
-          if (err) throw err;
-          assert.strictEqual(true, data.length > 0);
-          assert.strictEqual('jpeg', info.format);
-          assert.strictEqual(240, info.width);
-          assert.strictEqual(320, info.height);
-          done();
-        });
+  it('Invalid height - float', function () {
+    assert.throws(function () {
+      sharp().resize(320, 1.5);
     });
+  });
 
-    it('Max width or height considering ratio (portrait)', function (done) {
-      sharp(fixtures.inputTiff).resize(320, 320).max().jpeg().toBuffer(function (err, data, info) {
+  it('Invalid width - too large', function () {
+    assert.throws(function () {
+      sharp().resize(0x4000, 240);
+    });
+  });
+
+  it('Invalid height - too large', function () {
+    assert.throws(function () {
+      sharp().resize(320, 0x4000);
+    });
+  });
+
+  it('WebP shrink-on-load rounds to zero, ensure recalculation is correct', function (done) {
+    sharp(fixtures.inputJpg)
+      .resize(1080, 607)
+      .webp()
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual('webp', info.format);
+        assert.strictEqual(1080, info.width);
+        assert.strictEqual(607, info.height);
+        sharp(data)
+          .resize(233, 131)
+          .toBuffer(function (err, data, info) {
+            if (err) throw err;
+            assert.strictEqual('webp', info.format);
+            assert.strictEqual(233, info.width);
+            assert.strictEqual(131, info.height);
+            done();
+          });
+      });
+  });
+
+  it('TIFF embed known to cause rounding errors', function (done) {
+    sharp(fixtures.inputTiff)
+      .resize(240, 320)
+      .embed()
+      .jpeg()
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(240, info.width);
+        assert.strictEqual(320, info.height);
+        done();
+      });
+  });
+
+  it('TIFF known to cause rounding errors', function (done) {
+    sharp(fixtures.inputTiff)
+      .resize(240, 320)
+      .jpeg()
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(240, info.width);
+        assert.strictEqual(320, info.height);
+        done();
+      });
+  });
+
+  it('Max width or height considering ratio (portrait)', function (done) {
+    sharp(fixtures.inputTiff)
+      .resize(320, 320)
+      .max()
+      .jpeg()
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual('jpeg', info.format);
@@ -189,10 +162,14 @@ describe('Resize dimensions', function () {
         assert.strictEqual(320, info.height);
         done();
       });
-    });
+  });
 
-    it('Min width or height considering ratio (portrait)', function (done) {
-      sharp(fixtures.inputTiff).resize(320, 320).min().jpeg().toBuffer(function (err, data, info) {
+  it('Min width or height considering ratio (portrait)', function (done) {
+    sharp(fixtures.inputTiff)
+      .resize(320, 320)
+      .min()
+      .jpeg()
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual('jpeg', info.format);
@@ -200,51 +177,62 @@ describe('Resize dimensions', function () {
         assert.strictEqual(422, info.height);
         done();
       });
-    });
-  }
+  });
 
   it('Max width or height considering ratio (landscape)', function (done) {
-    sharp(fixtures.inputJpg).resize(320, 320).max().toBuffer(function (err, data, info) {
-      if (err) throw err;
-      assert.strictEqual(true, data.length > 0);
-      assert.strictEqual('jpeg', info.format);
-      assert.strictEqual(320, info.width);
-      assert.strictEqual(261, info.height);
-      done();
-    });
+    sharp(fixtures.inputJpg)
+      .resize(320, 320)
+      .max()
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(320, info.width);
+        assert.strictEqual(261, info.height);
+        done();
+      });
   });
 
   it('Provide only one dimension with max, should default to crop', function (done) {
-    sharp(fixtures.inputJpg).resize(320).max().toBuffer(function (err, data, info) {
-      if (err) throw err;
-      assert.strictEqual(true, data.length > 0);
-      assert.strictEqual('jpeg', info.format);
-      assert.strictEqual(320, info.width);
-      assert.strictEqual(261, info.height);
-      done();
-    });
+    sharp(fixtures.inputJpg)
+      .resize(320)
+      .max()
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(320, info.width);
+        assert.strictEqual(261, info.height);
+        done();
+      });
   });
 
   it('Min width or height considering ratio (landscape)', function (done) {
-    sharp(fixtures.inputJpg).resize(320, 320).min().toBuffer(function (err, data, info) {
-      if (err) throw err;
-      assert.strictEqual(true, data.length > 0);
-      assert.strictEqual('jpeg', info.format);
-      assert.strictEqual(392, info.width);
-      assert.strictEqual(320, info.height);
-      done();
-    });
+    sharp(fixtures.inputJpg)
+      .resize(320, 320)
+      .min()
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(392, info.width);
+        assert.strictEqual(320, info.height);
+        done();
+      });
   });
 
   it('Provide only one dimension with min, should default to crop', function (done) {
-    sharp(fixtures.inputJpg).resize(320).min().toBuffer(function (err, data, info) {
-      if (err) throw err;
-      assert.strictEqual(true, data.length > 0);
-      assert.strictEqual('jpeg', info.format);
-      assert.strictEqual(320, info.width);
-      assert.strictEqual(261, info.height);
-      done();
-    });
+    sharp(fixtures.inputJpg)
+      .resize(320)
+      .min()
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(320, info.width);
+        assert.strictEqual(261, info.height);
+        done();
+      });
   });
 
   it('Do not enlarge when input width is already less than output width', function (done) {
@@ -387,4 +375,31 @@ describe('Resize dimensions', function () {
       done();
     });
   });
+
+  it('Centre vs corner convention return different results', function (done) {
+    sharp(fixtures.inputJpg)
+      .resize(32, 24, { centreSampling: false })
+      .greyscale()
+      .raw()
+      .toBuffer(function (err, cornerData) {
+        if (err) throw err;
+        assert.strictEqual(768, cornerData.length);
+        sharp(fixtures.inputJpg)
+          .resize(32, 24, { centerSampling: true })
+          .greyscale()
+          .raw()
+          .toBuffer(function (err, centreData) {
+            if (err) throw err;
+            assert.strictEqual(768, centreData.length);
+            assert.notStrictEqual(0, cornerData.compare(centreData));
+            done();
+          });
+      });
+  });
+
+  it('Invalid centreSampling option', function () {
+    assert.throws(function () {
+      sharp().resize(32, 24, { centreSampling: 1 });
+    });
+  });
 });