Adding new ConsistentEmphasisStyleRule

markdown/src/main/kotlin/com/appmattus/markdown/processing/MarkdownDocument.kt

@@ -6,6 +6,7 @@ import com.vladsch.flexmark.ast.BlockQuote
 import com.vladsch.flexmark.ast.BulletList
 import com.vladsch.flexmark.ast.BulletListItem
 import com.vladsch.flexmark.ast.Code
+import com.vladsch.flexmark.ast.Emphasis
 import com.vladsch.flexmark.ast.FencedCodeBlock
 import com.vladsch.flexmark.ast.Heading
 import com.vladsch.flexmark.ast.HtmlBlock
@@ -22,6 +23,7 @@ import com.vladsch.flexmark.ast.OrderedList
 import com.vladsch.flexmark.ast.OrderedListItem
 import com.vladsch.flexmark.ast.Paragraph
 import com.vladsch.flexmark.ast.Reference
+import com.vladsch.flexmark.ast.StrongEmphasis
 import com.vladsch.flexmark.ast.Text
 import com.vladsch.flexmark.ast.ThematicBreak
 import com.vladsch.flexmark.ext.gfm.tasklist.TaskListItem
@@ -64,6 +66,8 @@ class MarkdownDocument(val filename: String, val document: Document) {
     val topLevelParagraphs: List<Paragraph> by lazy { document.find(Paragraph::class, visitChildren = false) }
     val allText by lazy { document.find(Text::class) }
 
+    val allEmphasis by lazy { document.find(Emphasis::class, StrongEmphasis::class) }
+
     val chars: BasedSequence by lazy { document.chars }
     val lines by lazy { chars.splitIntoLines() }
 

markdown/src/main/kotlin/com/appmattus/markdown/rules/ConsistentEmphasisStyleRule.kt

@@ -0,0 +1,81 @@
+package com.appmattus.markdown.rules
+
+import com.appmattus.markdown.dsl.RuleSetup
+import com.appmattus.markdown.errors.ErrorReporter
+import com.appmattus.markdown.processing.MarkdownDocument
+import com.appmattus.markdown.rules.config.EmphasisStyle
+import com.vladsch.flexmark.ast.DelimitedNode
+import com.vladsch.flexmark.ast.Emphasis
+
+/**
+ * # Emphasis marker style
+ *
+ * This rule is triggered when the symbols used in the document for italic and bold text do not match the configured
+ * emphasis marker style:
+ *
+ *     *Italic*
+ *     _Also italic_
+ *
+ * To fix this issue, use the configured style for emphasis markers throughout the document:
+ *
+ *     *Italic*
+ *     *Also italic*
+ *
+ * Note: the configured emphasis marker style can be a specific symbol ([EmphasisStyle.Asterisk],
+ * [EmphasisStyle.Underscore]), or simply require that the usage be [EmphasisStyle.Consistent] within the document.
+ */
+class ConsistentEmphasisStyleRule(
+    private val style: EmphasisStyle = EmphasisStyle.Asterisk,
+    override val config: RuleSetup.Builder.() -> Unit = {}
+) : Rule() {
+
+    override fun visitDocument(document: MarkdownDocument, errorReporter: ErrorReporter) {
+
+        val allEmphasis = document.allEmphasis
+
+        if (allEmphasis.isEmpty()) {
+            return
+        }
+
+        val docStyle = if (style == EmphasisStyle.Consistent) allEmphasis.first().style() else style
+
+        allEmphasis.forEach {
+            if (it.style() != docStyle) {
+                val type = if (it is Emphasis) "Italic" else "Bold"
+
+                val symbolCount = if (it is Emphasis) 1 else 2
+                val expected = docStyle.symbol().repeat(symbolCount)
+                val actual = it.style().symbol().repeat(symbolCount)
+
+                val description = "$type text expected to use '$expected' emphasis markers but is '$actual', for " +
+                        "example $expected${it.text}$expected. Configuration: style=${style.description()}."
+
+                errorReporter.reportError(it.startOffset, it.endOffset, description)
+            }
+        }
+    }
+
+    private fun DelimitedNode.style(): EmphasisStyle {
+        return when {
+            openingMarker.contains('*') -> EmphasisStyle.Asterisk
+            openingMarker.contains('_') -> EmphasisStyle.Underscore
+            else -> throw IllegalStateException()
+        }
+    }
+
+    private fun EmphasisStyle.symbol(): String {
+        return when (this) {
+            EmphasisStyle.Asterisk -> "*"
+            EmphasisStyle.Underscore -> "_"
+            else -> throw IllegalStateException()
+        }
+    }
+
+    private fun EmphasisStyle.description(): String {
+        return when (this) {
+            EmphasisStyle.Asterisk -> "Asterisk '*'"
+            EmphasisStyle.Underscore -> "Underscore '_'"
+            EmphasisStyle.Consistent -> "Consistent"
+        }
+    }
+}

markdown/src/main/kotlin/com/appmattus/markdown/rules/config/EmphasisStyle.kt

@@ -0,0 +1,5 @@
+package com.appmattus.markdown.rules.config
+
+enum class EmphasisStyle {
+    Consistent, Asterisk, Underscore
+}

markdown/src/test/kotlin/com/appmattus/markdown/rules/ConsistentEmphasisStyleRuleTest.kt

@@ -0,0 +1,19 @@
+package com.appmattus.markdown.rules
+
+import com.appmattus.markdown.rules.config.EmphasisStyle
+import org.spekframework.spek2.Spek
+import org.spekframework.spek2.style.gherkin.Feature
+
+object ConsistentEmphasisStyleRuleTest : Spek({
+    Feature("ConsistentEmphasisStyleRule") {
+        FileRuleScenario(files = listOf("consistent_emphasis_asterisk.md")) {
+            ConsistentEmphasisStyleRule(EmphasisStyle.Asterisk)
+        }
+
+        FileRuleScenario(files = listOf("consistent_emphasis_underscore.md")) {
+            ConsistentEmphasisStyleRule(EmphasisStyle.Underscore)
+        }
+
+        FileRuleScenario { ConsistentEmphasisStyleRule(EmphasisStyle.Consistent) }
+    }
+})

markdown/src/test/resources/consistent_emphasis_asterisk.md

@@ -0,0 +1,7 @@
+_This should violate {ConsistentEmphasisStyleRule}_
+
+*This will not*
+
+__This will also violate {ConsistentEmphasisStyleRule}__
+
+**But this will be fine**

markdown/src/test/resources/consistent_emphasis_underscore.md

@@ -0,0 +1,7 @@
+*This should violate {ConsistentEmphasisStyleRule}*
+
+_This will not_
+
+**This will also violate {ConsistentEmphasisStyleRule}**
+
+__But this will be fine__

markdown/src/test/resources/emphasis_instead_of_headers.md

@@ -7,7 +7,7 @@ Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore
 eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt
 in culpa qui officia deserunt mollit anim id est laborum.
 
-__Section 1.1: another section {NoEmphasisAsHeaderRule}__
+__Section 1.1: {NoEmphasisAsHeaderRule} {ConsistentEmphasisStyleRule}__
 
 Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor
 incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis
@@ -25,7 +25,7 @@ Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore
 eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt
 in culpa qui officia deserunt mollit anim id est laborum.
 
-_Section 3: oh no more sections {NoEmphasisAsHeaderRule}_
+_Section 3: {NoEmphasisAsHeaderRule} {ConsistentEmphasisStyleRule}_
 
 This is a normal paragraph
 **that just happens to have emphasized text in**

markdown/src/test/resources/fix_102_extra_nodes_in_link_text.md

@@ -6,3 +6,8 @@
 [test **test** test](www.test.com)
 [test __test__ test](www.test.com)
 [this should not raise](www.shouldnotraise.com)
+
+{ConsistentEmphasisStyleRule:3} {ConsistentEmphasisStyleRule:4}
+{ConsistentEmphasisStyleRule:4} {ConsistentEmphasisStyleRule:5}
+{ConsistentEmphasisStyleRule:5} {ConsistentEmphasisStyleRule:5}
+{ConsistentEmphasisStyleRule:6}

markdown/src/test/resources/long_lines.md

@@ -48,6 +48,8 @@ _**[This long line is comprised of an emphasized and bolded link](https://exampl
 
 {LineLengthRule:1} {LineLengthRule:11} {LineLengthRule:14}
 {LineLengthRule:19} {LineLengthRule:21}
+{ConsistentEmphasisStyleRule:35} {ConsistentEmphasisStyleRule:39}
+{ConsistentEmphasisStyleRule:41} {ConsistentEmphasisStyleRule:43}
 
 LineLengthRule:29 is invalid too but gets picked up as a link currently
 
@@ -58,13 +60,13 @@ This is a looooongish [line](https://example.com "This is the long link's title"
 This is a looongish [line](https://example.com "This is the long link's title")A
 This is a loooongish [line](https://example.com "This is the long link's title")B
 
-{LineLengthRule:59}
+{LineLengthRule:61}
 
 This is a long long long long long long long long long long long long loongish [line](https://example.com "This is the long link's title")
 This is a long long long long long long long long long long long long looongish [line](https://example.com "This is the long link's title")
 This is a long long long long long long long long long long long long loooongish [line](https://example.com "This is the long link's title")
 
-{LineLengthRule:64} {LineLengthRule:65}
+{LineLengthRule:66} {LineLengthRule:67}
 
 {NoReversedLinksRule:21} {NoReversedLinksRule:23} {NoReversedLinksRule:27}
 {NoEmptyLinksRule:27}

markdown/src/test/resources/proper-names.md

@@ -6,7 +6,7 @@ Quoted "Markdownlint" {ProperNamesRule}
 
 Emphasized *Markdownlint* {ProperNamesRule}
 
-Emphasized _Markdownlint_ {ProperNamesRule}
+Emphasized _Markdownlint_ {ProperNamesRule} {ConsistentEmphasisStyleRule}
 
 JavaScript is a language
 

markdown/src/test/resources/spaces_inside_emphasis_markers.md

@@ -2,9 +2,9 @@ Line with *Normal emphasis*
 
 Line with **Normal strong**
 
-Line with _Normal emphasis_
+Line with _Normal emphasis_ {ConsistentEmphasisStyleRule}
 
-Line with __Normal strong__
+Line with __Normal strong__ {ConsistentEmphasisStyleRule}
 
 Broken * emphasis * with spaces in {NoSpaceInEmphasisRule}
 
@@ -19,8 +19,10 @@ Mixed *ok emphasis* and * broken emphasis * {NoSpaceInEmphasisRule}
 Mixed **ok strong** and ** broken strong ** {NoSpaceInEmphasisRule}
 
 Mixed _ok emphasis_ and _ broken emphasis _ {NoSpaceInEmphasisRule}
+{ConsistentEmphasisStyleRule:21}
 
 Mixed __ok strong__ and __ broken strong __ {NoSpaceInEmphasisRule}
+{ConsistentEmphasisStyleRule:24}
 
 Mixed *ok emphasis* **ok strong** * broken emphasis * {NoSpaceInEmphasisRule}