Render code blocks in KDoc

idea/src/org/jetbrains/kotlin/idea/kdoc/KDocRenderer.kt

@@ -90,7 +90,7 @@ object KDocRenderer {
         val markdownNode = MarkdownNode(markdownTree, null, markdown)
 
         // Avoid wrapping the entire converted contents in a <p> tag if it's just a single paragraph
-        val maybeSingleParagraph = markdownNode.children.filter { it.type == MarkdownElementTypes.PARAGRAPH }.singleOrNull()
+        val maybeSingleParagraph = markdownNode.children.filter { it.type != MarkdownTokenTypes.EOL }.singleOrNull()
         if (maybeSingleParagraph != null) {
             return maybeSingleParagraph.children.map { it.toHtml() }.join("")
         } else {
@@ -142,13 +142,13 @@ object KDocRenderer {
                 MarkdownElementTypes.ATX_6 -> wrapChildren("h6")
                 MarkdownElementTypes.BLOCK_QUOTE -> wrapChildren("blockquote")
                 MarkdownElementTypes.PARAGRAPH -> {
-                    while (sb.length() > 0 && sb[sb.length() - 1] == ' ') {
-                        sb.deleteCharAt(sb.length() - 1)
-                    }
+                    sb.trimTrailing()
                     wrapChildren("p", newline = true)
                 }
                 MarkdownElementTypes.CODE_SPAN -> wrapChildren("code")
-                MarkdownElementTypes.CODE_BLOCK -> {
+                MarkdownElementTypes.CODE_BLOCK,
+                MarkdownElementTypes.CODE_FENCE -> {
+                    sb.trimTrailing()
                     sb.append("<pre><code>")
                     processChildren()
                     sb.append("</code><pre>")
@@ -159,7 +159,8 @@ object KDocRenderer {
                     if (label != null) {
                         val linkText = node.child(MarkdownElementTypes.LINK_TEXT)?.child(MarkdownTokenTypes.TEXT)?.text ?: label
                         DocumentationManagerUtil.createHyperlink(sb, label, linkText, true)
-                    } else {
+                    }
+                    else {
                         sb.append(node.text)
                     }
                 }
@@ -168,11 +169,13 @@ object KDocRenderer {
                     val destination = node.child(MarkdownElementTypes.LINK_DESTINATION)?.text
                     if (label != null && destination != null) {
                         sb.append("a href=\"${destination}\">${label.htmlEscape()}</a>")
-                    } else {
+                    }
+                    else {
                         sb.append(node.text)
                     }
                 }
                 MarkdownTokenTypes.TEXT,
+                MarkdownTokenTypes.CODE,
                 MarkdownTokenTypes.WHITE_SPACE,
                 MarkdownTokenTypes.COLON,
                 MarkdownTokenTypes.SINGLE_QUOTE,
@@ -184,7 +187,13 @@ object KDocRenderer {
                     sb.append(nodeText)
                 }
                 MarkdownTokenTypes.EOL -> {
-                    sb.append(" ")
+                    val parentType = node.parent?.type
+                    if (parentType == MarkdownElementTypes.CODE_BLOCK || parentType == MarkdownElementTypes.CODE_FENCE) {
+                        sb.append("\n")
+                    }
+                    else {
+                        sb.append(" ")
+                    }
                 }
                 MarkdownTokenTypes.GT -> sb.append("&gt;")
                 MarkdownTokenTypes.LT -> sb.append("&lt;")
@@ -196,5 +205,11 @@ object KDocRenderer {
         return sb.toString()
     }
 
+    fun StringBuilder.trimTrailing() {
+        while (length() > 0 && this[length() - 1] == ' ') {
+            deleteCharAt(length() - 1)
+        }
+    }
+
     fun String.htmlEscape(): String = replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
 }

idea/testData/editor/quickDoc/OnMethodUsageWithCodeBlock.kt

@@ -0,0 +1,26 @@
+/**
+ * Some documentation.
+ *
+ * ```
+ * Code block
+ * Second line
+ * ```
+ */
+fun testMethod() {
+
+}
+
+class C {
+}
+
+fun test() {
+    <caret>testMethod(1, "value")
+}
+
+//INFO: <b>internal</b> <b>fun</b> testMethod(): Unit <i>defined in</i> root package<br/><p><p>
+//INFO: Some documentation.</p>
+//INFO:   <pre><code>
+//INFO: Code block
+//INFO: Second line
+//INFO: </code><pre>
+//INFO: </p>

idea/tests/org/jetbrains/kotlin/idea/editor/quickDoc/JetQuickDocProviderTestGenerated.java

@@ -125,6 +125,12 @@ public class JetQuickDocProviderTestGenerated extends AbstractJetQuickDocProvide
         doTest(fileName);
     }
 
+    @TestMetadata("OnMethodUsageWithCodeBlock.kt")
+    public void testOnMethodUsageWithCodeBlock() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/testData/editor/quickDoc/OnMethodUsageWithCodeBlock.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("OnMethodUsageWithMarkdown.kt")
     public void testOnMethodUsageWithMarkdown() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/testData/editor/quickDoc/OnMethodUsageWithMarkdown.kt");