Add spec

app/assets/javascripts/copy_as_gfm.js

@@ -273,12 +273,12 @@ const gfmRules = {
 
 class CopyAsGFM {
   constructor() {
-    $(document).on('copy', '.md, .wiki', (e) => { this.copyAsGFM(e, CopyAsGFM.transformGFMSelection); });
-    $(document).on('copy', 'pre.code.highlight, .diff-content .line_content', (e) => { this.copyAsGFM(e, CopyAsGFM.transformCodeSelection); });
-    $(document).on('paste', '.js-gfm-input', this.pasteGFM.bind(this));
+    $(document).on('copy', '.md, .wiki', (e) => { CopyAsGFM.copyAsGFM(e, CopyAsGFM.transformGFMSelection); });
+    $(document).on('copy', 'pre.code.highlight, .diff-content .line_content', (e) => { CopyAsGFM.copyAsGFM(e, CopyAsGFM.transformCodeSelection); });
+    $(document).on('paste', '.js-gfm-input', CopyAsGFM.pasteGFM);
   }
 
-  copyAsGFM(e, transformer) {
+  static copyAsGFM(e, transformer) {
     const clipboardData = e.originalEvent.clipboardData;
     if (!clipboardData) return;
 
@@ -292,10 +292,10 @@ class CopyAsGFM {
     e.stopPropagation();
 
     clipboardData.setData('text/plain', el.textContent);
-    clipboardData.setData('text/x-gfm', CopyAsGFM.nodeToGFM(el));
+    clipboardData.setData('text/x-gfm', this.nodeToGFM(el));
   }
 
-  pasteGFM(e) {
+  static pasteGFM(e) {
     const clipboardData = e.originalEvent.clipboardData;
     if (!clipboardData) return;
 

spec/javascripts/copy_as_gfm_spec.js

+require('~/copy_as_gfm');
+
+(() => {
+  describe('gl.CopyAsGFM', () => {
+    describe('gl.CopyAsGFM.pasteGFM', () => {
+      function callPasteGFM() {
+        const e = {
+          originalEvent: {
+            clipboardData: {
+              getData(mimeType) {
+                // When GFM code is copied, we put the regular plain text
+                // on the clipboard as `text/plain`, and the GFM as `text/x-gfm`.
+                // This emulates the behavior of `getData` with that data.
+                if (mimeType === 'text/plain') {
+                  return 'code';
+                }
+                if (mimeType === 'text/x-gfm') {
+                  return '`code`';
+                }
+                return null;
+              },
+            },
+          },
+          preventDefault() {},
+        };
+
+        window.gl.CopyAsGFM.pasteGFM(e);
+      }
+
+      it('wraps pasted code when not already in code tags', () => {
+        spyOn(window.gl.utils, 'insertText').and.callFake((el, textFunc) => {
+          const insertedText = textFunc('This is code: ', '');
+          expect(insertedText).toEqual('`code`');
+        });
+
+        callPasteGFM();
+      });
+
+      it('does not wrap pasted code when already in code tags', () => {
+        spyOn(window.gl.utils, 'insertText').and.callFake((el, textFunc) => {
+          const insertedText = textFunc('This is code: `', '`');
+          expect(insertedText).toEqual('code');
+        });
+
+        callPasteGFM();
+      });
+    });
+  });
+})();