handle code blocks escaped with multiple backticks correctly; generate extra backticks if text in code block contains backticks (KT-12998, KT-12999)

3 files changed, 27 insertions, 1 deletions

diff --git a/core/src/main/kotlin/Formats/MarkdownFormatService.kt b/core/src/main/kotlin/Formats/MarkdownFormatService.kt
index 6f2ab327..2e3c9f6d 100644
--- a/core/src/main/kotlin/Formats/MarkdownFormatService.kt
+++ b/core/src/main/kotlin/Formats/MarkdownFormatService.kt
@@ -19,6 +19,7 @@ open class MarkdownOutputBuilder(to: StringBuilder,
     protected var inTableCell = false
     protected var inCodeBlock = false
     private var lastTableCellStart = -1
+    private var maxBackticksInCodeBlock = 0
 
     private fun appendNewline() {
         while (to.endsWith(' ')) {
@@ -64,9 +65,14 @@ open class MarkdownOutputBuilder(to: StringBuilder,
         to.append(" / ")
     }
 
+    private val backTickFindingRegex = """(`+)""".toRegex()
+
     override fun appendText(text: String) {
         if (inCodeBlock) {
             to.append(text)
+            val backTicks = backTickFindingRegex.findAll(text)
+            val longestBackTickRun = backTicks.map { it.value.length }.max() ?: 0
+            maxBackticksInCodeBlock = maxBackticksInCodeBlock.coerceAtLeast(longestBackTickRun)
         }
         else {
             to.append(text.htmlEscape())
@@ -75,7 +81,17 @@ open class MarkdownOutputBuilder(to: StringBuilder,
 
     override fun appendCode(body: () -> Unit) {
         inCodeBlock = true
+        val codeBlockStart = to.length
+        maxBackticksInCodeBlock = 0
+
         wrapIfNotEmpty("`", "`", body, checkEndsWith = true)
+
+        if (maxBackticksInCodeBlock > 0) {
+            val extraBackticks = "`".repeat(maxBackticksInCodeBlock)
+            to.insert(codeBlockStart, extraBackticks)
+            to.append(extraBackticks)
+        }
+
         inCodeBlock = false
     }
 
diff --git a/core/src/main/kotlin/Kotlin/ContentBuilder.kt b/core/src/main/kotlin/Kotlin/ContentBuilder.kt
index c16b19c5..7bee6936 100644
--- a/core/src/main/kotlin/Kotlin/ContentBuilder.kt
+++ b/core/src/main/kotlin/Kotlin/ContentBuilder.kt
@@ -43,7 +43,12 @@ fun buildContentTo(tree: MarkdownNode, target: ContentBlock, linkResolver: (Stri
             MarkdownElementTypes.EMPH -> appendNodeWithChildren(ContentEmphasis())
             MarkdownElementTypes.STRONG -> appendNodeWithChildren(ContentStrong())
             MarkdownElementTypes.CODE_SPAN -> {
-                appendNodeWithChildren(ContentCode())
+                val startDelimiter = node.child(MarkdownTokenTypes.BACKTICK)?.text
+                if (startDelimiter != null) {
+                    val text = node.text.substring(startDelimiter.length).removeSuffix(startDelimiter)
+                    val codeSpan = ContentCode().apply { append(ContentText(text)) }
+                    parent.append(codeSpan)
+                }
             }
             MarkdownElementTypes.CODE_BLOCK,
             MarkdownElementTypes.CODE_FENCE -> appendNodeWithChildren(ContentBlockCode())
@@ -126,6 +131,7 @@ fun buildContentTo(tree: MarkdownNode, target: ContentBlock, linkResolver: (Stri
             MarkdownTokenTypes.LBRACKET,
             MarkdownTokenTypes.RBRACKET,
             MarkdownTokenTypes.EXCLAMATION_MARK,
+            MarkdownTokenTypes.BACKTICK,
             MarkdownTokenTypes.CODE_FENCE_CONTENT -> {
                 parent.append(ContentText(node.text))
             }
diff --git a/core/src/test/kotlin/format/MarkdownFormatTest.kt b/core/src/test/kotlin/format/MarkdownFormatTest.kt
index 00bbdd61..864fb9d1 100644
--- a/core/src/test/kotlin/format/MarkdownFormatTest.kt
+++ b/core/src/test/kotlin/format/MarkdownFormatTest.kt
@@ -214,6 +214,10 @@ class MarkdownFormatTest {
         verifyMarkdownNodeByName("exclInCodeBlock", "foo")
     }
 
+    @Test fun backtickInCodeBlock() {
+        verifyMarkdownNodeByName("backtickInCodeBlock", "foo")
+    }
+
     private fun verifyMarkdownPackage(fileName: String, withKotlinRuntime: Boolean = false) {
         verifyOutput("testdata/format/$fileName.kt", ".package.md", withKotlinRuntime = withKotlinRuntime) { model, output ->
             markdownService.createOutputBuilder(output, tempLocation).appendNodes(model.members)