From ec66829b7541b2539cc2126b8f4df4414e2607b8 Mon Sep 17 00:00:00 2001
From: Robin Stocker <robin@nibor.org>
Date: Tue, 16 Jan 2024 22:30:52 +1100
Subject: [PATCH] Add markerIndent and contentIndent to ListItem

This information is required for a renderer producing Markdown.
---
 .../commonmark/internal/ListBlockParser.java  |  2 +-
 .../commonmark/internal/ListItemParser.java   |  4 +-
 .../java/org/commonmark/node/ListItem.java    | 45 +++++++++++++
 .../commonmark/test/ListBlockParserTest.java  | 67 +++++++++++++++++++
 .../test/java/org/commonmark/test/Nodes.java  | 23 +++++++
 5 files changed, 139 insertions(+), 2 deletions(-)
 create mode 100644 commonmark/src/test/java/org/commonmark/test/ListBlockParserTest.java

diff --git a/commonmark/src/main/java/org/commonmark/internal/ListBlockParser.java b/commonmark/src/main/java/org/commonmark/internal/ListBlockParser.java
index f6702518b..0ff644a47 100644
--- a/commonmark/src/main/java/org/commonmark/internal/ListBlockParser.java
+++ b/commonmark/src/main/java/org/commonmark/internal/ListBlockParser.java
@@ -217,7 +217,7 @@ public BlockStart tryStart(ParserState state, MatchedBlockParser matchedBlockPar
             }
 
             int newColumn = listData.contentColumn;
-            ListItemParser listItemParser = new ListItemParser(newColumn - state.getColumn());
+            ListItemParser listItemParser = new ListItemParser(state.getIndent(), newColumn - state.getColumn());
 
             // prepend the list block if needed
             if (!(matched instanceof ListBlockParser) ||
diff --git a/commonmark/src/main/java/org/commonmark/internal/ListItemParser.java b/commonmark/src/main/java/org/commonmark/internal/ListItemParser.java
index 6f03770b3..49722dff2 100644
--- a/commonmark/src/main/java/org/commonmark/internal/ListItemParser.java
+++ b/commonmark/src/main/java/org/commonmark/internal/ListItemParser.java
@@ -20,8 +20,10 @@ public class ListItemParser extends AbstractBlockParser {
 
     private boolean hadBlankLine;
 
-    public ListItemParser(int contentIndent) {
+    public ListItemParser(int markerIndent, int contentIndent) {
         this.contentIndent = contentIndent;
+        block.setMarkerIndent(markerIndent);
+        block.setContentIndent(contentIndent);
     }
 
     @Override
diff --git a/commonmark/src/main/java/org/commonmark/node/ListItem.java b/commonmark/src/main/java/org/commonmark/node/ListItem.java
index aa526be01..21f4e2b82 100644
--- a/commonmark/src/main/java/org/commonmark/node/ListItem.java
+++ b/commonmark/src/main/java/org/commonmark/node/ListItem.java
@@ -2,8 +2,53 @@
 
 public class ListItem extends Block {
 
+    private int markerIndent;
+    private int contentIndent;
+
     @Override
     public void accept(Visitor visitor) {
         visitor.visit(this);
     }
+
+    /**
+     * Returns the indent of the marker such as "-" or "1." in columns (spaces or tab stop of 4).
+     * <p>
+     * Some examples and their marker indent:
+     * <pre>- Foo</pre>
+     * Marker indent: 0
+     * <pre> - Foo</pre>
+     * Marker indent: 1
+     * <pre>  1. Foo</pre>
+     * Marker indent: 2
+     */
+    public int getMarkerIndent() {
+        return markerIndent;
+    }
+
+    public void setMarkerIndent(int markerIndent) {
+        this.markerIndent = markerIndent;
+    }
+
+    /**
+     * Returns the indent of the content in columns (spaces or tab stop of 4). The content indent is counted from the
+     * beginning of the line and includes the marker on the first line.
+     * <p>
+     * Some examples and their content indent:
+     * <pre>- Foo</pre>
+     * Content indent: 2
+     * <pre> - Foo</pre>
+     * Content indent: 3
+     * <pre>  1. Foo</pre>
+     * Content indent: 5
+     * <p>
+     * Note that subsequent lines in the same list item need to be indented by at least the content indent to be counted
+     * as part of the list item.
+     */
+    public int getContentIndent() {
+        return contentIndent;
+    }
+
+    public void setContentIndent(int contentIndent) {
+        this.contentIndent = contentIndent;
+    }
 }
diff --git a/commonmark/src/test/java/org/commonmark/test/ListBlockParserTest.java b/commonmark/src/test/java/org/commonmark/test/ListBlockParserTest.java
new file mode 100644
index 000000000..a8a03fb74
--- /dev/null
+++ b/commonmark/src/test/java/org/commonmark/test/ListBlockParserTest.java
@@ -0,0 +1,67 @@
+package org.commonmark.test;
+
+import org.commonmark.node.ListItem;
+import org.commonmark.node.Node;
+import org.commonmark.parser.Parser;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class ListBlockParserTest {
+
+    private static final Parser PARSER = Parser.builder().build();
+
+    @Test
+    public void testBulletListIndents() {
+        assertListItemIndents("* foo", 0, 2);
+        assertListItemIndents(" * foo", 1, 3);
+        assertListItemIndents("  * foo", 2, 4);
+        assertListItemIndents("   * foo", 3, 5);
+
+        assertListItemIndents("*  foo", 0, 3);
+        assertListItemIndents("*   foo", 0, 4);
+        assertListItemIndents("*    foo", 0, 5);
+        assertListItemIndents(" *  foo", 1, 4);
+        assertListItemIndents("   *    foo", 3, 8);
+
+        // The indent is relative to any containing blocks
+        assertListItemIndents("> * foo", 0, 2);
+        assertListItemIndents(">  * foo", 1, 3);
+        assertListItemIndents(">  *  foo", 1, 4);
+
+        // Tab counts as 3 spaces here (to the next tab stop column of 4) -> content indent is 1+3
+        assertListItemIndents("*\tfoo", 0, 4);
+
+        // Empty list, content indent is expected to be 2
+        assertListItemIndents("-\n", 0, 2);
+    }
+
+    @Test
+    public void testOrderedListIndents() {
+        assertListItemIndents("1. foo", 0, 3);
+        assertListItemIndents(" 1. foo", 1, 4);
+        assertListItemIndents("  1. foo", 2, 5);
+        assertListItemIndents("   1. foo", 3, 6);
+
+        assertListItemIndents("1.  foo", 0, 4);
+        assertListItemIndents("1.   foo", 0, 5);
+        assertListItemIndents("1.    foo", 0, 6);
+        assertListItemIndents(" 1.  foo", 1, 5);
+        assertListItemIndents("  1.    foo", 2, 8);
+
+        assertListItemIndents("> 1. foo", 0, 3);
+        assertListItemIndents(">  1. foo", 1, 4);
+        assertListItemIndents(">  1.  foo", 1, 5);
+
+        assertListItemIndents("1.\tfoo", 0, 4);
+    }
+
+    private void assertListItemIndents(String input, int expectedMarkerIndent, int expectedContentIndent) {
+        Node doc = PARSER.parse(input);
+        ListItem listItem = Nodes.find(doc, ListItem.class);
+        assertNotNull(listItem);
+        assertEquals(expectedMarkerIndent, listItem.getMarkerIndent());
+        assertEquals(expectedContentIndent, listItem.getContentIndent());
+    }
+}
diff --git a/commonmark/src/test/java/org/commonmark/test/Nodes.java b/commonmark/src/test/java/org/commonmark/test/Nodes.java
index bbc019a6a..25ce75836 100644
--- a/commonmark/src/test/java/org/commonmark/test/Nodes.java
+++ b/commonmark/src/test/java/org/commonmark/test/Nodes.java
@@ -14,4 +14,27 @@ public static List<Node> getChildren(Node parent) {
         }
         return children;
     }
+
+    /**
+     * Recursively try to find a node with the given type within the children of the specified node.
+     *
+     * @param parent    The node to get children from (node itself will not be checked)
+     * @param nodeClass The type of node to find
+     */
+    public static <T> T find(Node parent, Class<T> nodeClass) {
+        Node node = parent.getFirstChild();
+        while (node != null) {
+            Node next = node.getNext();
+            if (nodeClass.isInstance(node)) {
+                //noinspection unchecked
+                return (T) node;
+            }
+            T result = find(node, nodeClass);
+            if (result != null) {
+                return result;
+            }
+            node = next;
+        }
+        return null;
+    }
 }