Merge pull request #38 from imjohnbo/imjohnbo/fix-edge-link-paste

Fix Microsoft Edge link paste

Author: theinterned

src/paste-markdown-html.ts

@@ -12,6 +12,8 @@ type MarkdownTransformer = (element: HTMLElement | HTMLAnchorElement, args: stri
 
 function onPaste(event: ClipboardEvent) {
   const transfer = event.clipboardData
+  // if there is no clipboard data, or
+  // if there is no html content in the clipboard, return
   if (!transfer || !hasHTML(transfer)) return
 
   const field = event.currentTarget
@@ -52,8 +54,10 @@ function transform(
   for (const element of elements) {
     const textContent = element.textContent || ''
     const {part, index} = trimAfter(text, textContent)
-    markdownParts.push(part.replace(textContent, transformer(element, args)))
-    text = text.slice(index)
+    if (index >= 0) {
+      markdownParts.push(part.replace(textContent, transformer(element, args)))
+      text = text.slice(index)
+    }
   }
   markdownParts.push(text)
   return markdownParts.join('')

test/test.js

@@ -147,6 +147,23 @@ describe('paste-markdown', function () {
       paste(textarea, {'text/html': sentence, 'text/plain': plaintextSentence})
       assert.equal(textarea.value, markdownSentence)
     })
+
+    it("doesn't render any markdown for html link without corresponding plaintext", function () {
+      // eslint-disable-next-line github/unescaped-html-literal
+      const link = `<meta charset='utf-8'><a href="https://github.com/monalisa/playground/issues/1">
+        Link pasting · Issue #1 · monalisa/playground (github.com)</a>`
+      const plaintextLink = 'https://github.com/monalisa/playground/issues/1'
+      const linkPreviewLink = {
+        domain: 'github.com',
+        preferred_format: 'text/html;content=titled-hyperlink',
+        title: 'Link pasting · Issue #1 · monalisa/playground (github.com)',
+        type: 'website',
+        url: 'https://github.com/monalisa/playground/issues/1'
+      }
+
+      paste(textarea, {'text/html': link, 'text/plain': plaintextLink, 'text/link-preview': linkPreviewLink})
+      assert.equal(textarea.value, '')
+    })
   })
 })