Fix using `@` symbol inside code block (#2418)

1 files changed, 77 insertions, 4 deletions

diff --git a/plugins/base/src/main/kotlin/parsers/Parser.kt b/plugins/base/src/main/kotlin/parsers/Parser.kt
index 960d7a64..af07ec53 100644
--- a/plugins/base/src/main/kotlin/parsers/Parser.kt
+++ b/plugins/base/src/main/kotlin/parsers/Parser.kt
@@ -1,6 +1,8 @@
 package org.jetbrains.dokka.base.parsers
 
 import org.jetbrains.dokka.model.doc.*
+import org.jetbrains.dokka.model.doc.Deprecated
+import org.jetbrains.dokka.model.doc.Suppress
 
 abstract class Parser {
 
@@ -9,7 +11,7 @@ abstract class Parser {
     abstract fun preparse(text: String): String
 
     open fun parse(text: String): DocumentationNode =
-        DocumentationNode(jkdocToListOfPairs(preparse(text)).map { (tag, content) -> parseTagWithBody(tag, content) })
+        DocumentationNode(extractTagsToListOfPairs(preparse(text)).map { (tag, content) -> parseTagWithBody(tag, content) })
 
     open fun parseTagWithBody(tagName: String, content: String): TagWrapper =
         when (tagName) {
@@ -47,12 +49,83 @@ abstract class Parser {
             else -> CustomTagWrapper(parseStringToDocNode(content), tagName)
         }
 
-    private fun jkdocToListOfPairs(javadoc: String): List<Pair<String, String>> =
-        "description $javadoc"
-            .split("\n@")
+    /**
+     * KDoc parser from Kotlin compiler relies on a comment asterisk
+     * So there is a mini parser here
+     * TODO: at least to adapt [org.jetbrains.kotlin.kdoc.lexer.KDocLexer] to analyze KDoc without the asterisks and use it here
+     */
+    private fun extractTagsToListOfPairs(text: String): List<Pair<String, String>> =
+        "description $text"
+            .extractKDocSections()
             .map { content ->
                 val contentWithEscapedAts = content.replace("\\@", "@")
                 val (tag, body) = contentWithEscapedAts.split(" ", limit = 2)
                 tag to body
             }
+
+    /**
+     * Ignore a doc tag inside code spans and blocks
+     * @see org.jetbrains.kotlin.kdoc.psi.impl.KDocSection
+     */
+    private fun CharSequence.extractKDocSections(delimiter: String = "\n@"): List<String> {
+        var countOfBackticks = 0
+        var countOfTildes = 0
+        var countOfBackticksInOpeningFence = 0
+        var countOfTildesInOpeningFence = 0
+
+        var isInCode = false
+        val result = mutableListOf<String>()
+        var rangeStart = 0
+        var rangeEnd = 0
+        var currentOffset = 0
+        while (currentOffset < length) {
+
+            when (get(currentOffset)) {
+                '`' -> {
+                    countOfBackticks++
+                    countOfTildes = 0
+                }
+                '~' -> {
+                    countOfTildes++
+                    countOfBackticks = 0
+                }
+                else -> {
+                    if (isInCode) {
+                        // The closing code fence must be at least as long as the opening fence
+                        if(countOfBackticks >= countOfBackticksInOpeningFence
+                                || countOfTildes >= countOfTildesInOpeningFence)
+                            isInCode = false
+                    } else {
+                        // as per CommonMark spec, there can be any number of backticks for a code span, not only one or three
+                        if (countOfBackticks > 0) {
+                            isInCode = true
+                            countOfBackticksInOpeningFence = countOfBackticks
+                            countOfTildesInOpeningFence = Int.MAX_VALUE
+                        }
+                        // tildes are only for a code block, not code span
+                        if (countOfTildes >= 3) {
+                            isInCode = true
+                            countOfTildesInOpeningFence = countOfTildes
+                            countOfBackticksInOpeningFence = Int.MAX_VALUE
+                        }
+                    }
+                    countOfTildes = 0
+                    countOfBackticks = 0
+                }
+            }
+            if (!isInCode && startsWith(delimiter, currentOffset)) {
+                result.add(substring(rangeStart, rangeEnd))
+                currentOffset += delimiter.length
+                rangeStart = currentOffset
+                rangeEnd = currentOffset
+                continue
+            }
+
+            ++rangeEnd
+            ++currentOffset
+        }
+        result.add(substring(rangeStart, rangeEnd))
+        return result
+    }
+
 }