Handling of numbered markdown lists.
Fixes issue #5416
diff --git a/src/comment.rs b/src/comment.rs
index bc0e877..85918ec 100644
--- a/src/comment.rs
+++ b/src/comment.rs
@@ -432,12 +432,18 @@
/// Block that is formatted as an item.
///
-/// An item starts with either a star `*` a dash `-` a greater-than `>` or a plus '+'.
+/// An item starts with either a star `*`, a dash `-`, a greater-than `>`, a plus '+', or a number
+/// `12.` or `34)` (with at most 2 digits). An item represents CommonMark's ["list
+/// items"](https://spec.commonmark.org/0.30/#list-items) and/or ["block
+/// quotes"](https://spec.commonmark.org/0.30/#block-quotes), but note that only a subset of
+/// CommonMark is recognized - see the doc comment of [`ItemizedBlock::get_marker_length`] for more
+/// details.
+///
/// Different level of indentation are handled by shrinking the shape accordingly.
struct ItemizedBlock {
/// the lines that are identified as part of an itemized block
lines: Vec<String>,
- /// the number of characters (typically whitespaces) up to the item sigil
+ /// the number of characters (typically whitespaces) up to the item marker
indent: usize,
/// the string that marks the start of an item
opener: String,
@@ -446,37 +452,70 @@
}
impl ItemizedBlock {
- /// Returns `true` if the line is formatted as an item
- fn is_itemized_line(line: &str) -> bool {
- let trimmed = line.trim_start();
+ /// Checks whether the `trimmed` line includes an item marker. Returns `None` if there is no
+ /// marker. Returns the length of the marker (in bytes) if one is present. Note that the length
+ /// includes the whitespace that follows the marker, for example the marker in `"* list item"`
+ /// has the length of 2.
+ ///
+ /// This function recognizes item markers that correspond to CommonMark's
+ /// ["bullet list marker"](https://spec.commonmark.org/0.30/#bullet-list-marker),
+ /// ["block quote marker"](https://spec.commonmark.org/0.30/#block-quote-marker), and/or
+ /// ["ordered list marker"](https://spec.commonmark.org/0.30/#ordered-list-marker).
+ ///
+ /// Compared to CommonMark specification, the number of digits that are allowed in an ["ordered
+ /// list marker"](https://spec.commonmark.org/0.30/#ordered-list-marker) is more limited (to at
+ /// most 2 digits). Limiting the length of the marker helps reduce the risk of recognizing
+ /// arbitrary numbers as markers. See also
+ /// <https://talk.commonmark.org/t/blank-lines-before-lists-revisited/1990> which gives the
+ /// following example where a number (i.e. "1868") doesn't signify an ordered list:
+ /// ```md
+ /// The Captain died in
+ /// 1868. He wes buried in...
+ /// ```
+ fn get_marker_length(trimmed: &str) -> Option<usize> {
+ // https://spec.commonmark.org/0.30/#bullet-list-marker or
+ // https://spec.commonmark.org/0.30/#block-quote-marker
let itemized_start = ["* ", "- ", "> ", "+ "];
- itemized_start.iter().any(|s| trimmed.starts_with(s))
+ if itemized_start.iter().any(|s| trimmed.starts_with(s)) {
+ return Some(2); // All items in `itemized_start` have length 2.
+ }
+
+ // https://spec.commonmark.org/0.30/#ordered-list-marker, where at most 2 digits are
+ // allowed.
+ for suffix in [". ", ") "] {
+ if let Some((prefix, _)) = trimmed.split_once(suffix) {
+ if prefix.len() <= 2 && prefix.chars().all(|c| char::is_ascii_digit(&c)) {
+ return Some(prefix.len() + suffix.len());
+ }
+ }
+ }
+
+ None // No markers found.
}
- /// Creates a new ItemizedBlock described with the given line.
- /// The `is_itemized_line` needs to be called first.
- fn new(line: &str) -> ItemizedBlock {
- let space_to_sigil = line.chars().take_while(|c| c.is_whitespace()).count();
- // +2 = '* ', which will add the appropriate amount of whitespace to keep itemized
- // content formatted correctly.
- let mut indent = space_to_sigil + 2;
+ /// Creates a new `ItemizedBlock` described with the given `line`.
+ /// Returns `None` if `line` doesn't start an item.
+ fn new(line: &str) -> Option<ItemizedBlock> {
+ let marker_length = ItemizedBlock::get_marker_length(line.trim_start())?;
+ let space_to_marker = line.chars().take_while(|c| c.is_whitespace()).count();
+ let mut indent = space_to_marker + marker_length;
let mut line_start = " ".repeat(indent);
// Markdown blockquote start with a "> "
if line.trim_start().starts_with(">") {
// remove the original +2 indent because there might be multiple nested block quotes
// and it's easier to reason about the final indent by just taking the length
- // of th new line_start. We update the indent because it effects the max width
+ // of the new line_start. We update the indent because it effects the max width
// of each formatted line.
line_start = itemized_block_quote_start(line, line_start, 2);
indent = line_start.len();
}
- ItemizedBlock {
+ Some(ItemizedBlock {
lines: vec![line[indent..].to_string()],
indent,
opener: line[..indent].to_string(),
line_start,
- }
+ })
}
/// Returns a `StringFormat` used for formatting the content of an item.
@@ -495,7 +534,7 @@
/// Returns `true` if the line is part of the current itemized block.
/// If it is, then it is added to the internal lines list.
fn add_line(&mut self, line: &str) -> bool {
- if !ItemizedBlock::is_itemized_line(line)
+ if ItemizedBlock::get_marker_length(line.trim_start()).is_none()
&& self.indent <= line.chars().take_while(|c| c.is_whitespace()).count()
{
self.lines.push(line.to_string());
@@ -766,10 +805,11 @@
self.item_block = None;
if let Some(stripped) = line.strip_prefix("```") {
self.code_block_attr = Some(CodeBlockAttribute::new(stripped))
- } else if self.fmt.config.wrap_comments() && ItemizedBlock::is_itemized_line(line) {
- let ib = ItemizedBlock::new(line);
- self.item_block = Some(ib);
- return false;
+ } else if self.fmt.config.wrap_comments() {
+ if let Some(ib) = ItemizedBlock::new(line) {
+ self.item_block = Some(ib);
+ return false;
+ }
}
if self.result == self.opener {
@@ -2020,4 +2060,96 @@
"#;
assert_eq!(s, filter_normal_code(s_with_comment));
}
+
+ #[test]
+ fn test_itemized_block_first_line_handling() {
+ fn run_test(
+ test_input: &str,
+ expected_line: &str,
+ expected_indent: usize,
+ expected_opener: &str,
+ expected_line_start: &str,
+ ) {
+ let block = ItemizedBlock::new(test_input).unwrap();
+ assert_eq!(1, block.lines.len(), "test_input: {:?}", test_input);
+ assert_eq!(
+ expected_line, &block.lines[0],
+ "test_input: {:?}",
+ test_input
+ );
+ assert_eq!(
+ expected_indent, block.indent,
+ "test_input: {:?}",
+ test_input
+ );
+ assert_eq!(
+ expected_opener, &block.opener,
+ "test_input: {:?}",
+ test_input
+ );
+ assert_eq!(
+ expected_line_start, &block.line_start,
+ "test_input: {:?}",
+ test_input
+ );
+ }
+
+ run_test("- foo", "foo", 2, "- ", " ");
+ run_test("* foo", "foo", 2, "* ", " ");
+ run_test("> foo", "foo", 2, "> ", "> ");
+
+ run_test("1. foo", "foo", 3, "1. ", " ");
+ run_test("12. foo", "foo", 4, "12. ", " ");
+ run_test("1) foo", "foo", 3, "1) ", " ");
+ run_test("12) foo", "foo", 4, "12) ", " ");
+
+ run_test(" - foo", "foo", 6, " - ", " ");
+
+ // https://spec.commonmark.org/0.30 says: "A start number may begin with 0s":
+ run_test("0. foo", "foo", 3, "0. ", " ");
+ run_test("01. foo", "foo", 4, "01. ", " ");
+ }
+
+ #[test]
+ fn test_itemized_block_nonobvious_markers_are_rejected() {
+ let test_inputs = vec![
+ // Non-numeric item markers (e.g. `a.` or `iv.`) are not allowed by
+ // https://spec.commonmark.org/0.30/#ordered-list-marker. We also note that allowing
+ // them would risk misidentifying regular words as item markers. See also the
+ // discussion in https://talk.commonmark.org/t/blank-lines-before-lists-revisited/1990
+ "word. rest of the paragraph.",
+ "a. maybe this is a list item? maybe not?",
+ "iv. maybe this is a list item? maybe not?",
+ // Numbers with 3 or more digits are not recognized as item markers, to avoid
+ // formatting the following example as a list:
+ //
+ // ```
+ // The Captain died in
+ // 1868. He was buried in...
+ // ```
+ "123. only 2-digit numbers are recognized as item markers.",
+ // Parens:
+ "123) giving some coverage to parens as well.",
+ "a) giving some coverage to parens as well.",
+ // https://spec.commonmark.org/0.30 says that "at least one space or tab is needed
+ // between the list marker and any following content":
+ "1.Not a list item.",
+ "1.2.3. Not a list item.",
+ "1)Not a list item.",
+ "-Not a list item.",
+ "+Not a list item.",
+ "+1 not a list item.",
+ // https://spec.commonmark.org/0.30 says: "A start number may not be negative":
+ "-1. Not a list item.",
+ "-1 Not a list item.",
+ ];
+ for line in test_inputs.iter() {
+ let maybe_block = ItemizedBlock::new(line);
+ assert!(
+ maybe_block.is_none(),
+ "The following line shouldn't be classified as a list item: {}",
+ line
+ );
+ }
+ }
}
diff --git a/tests/source/itemized-blocks/no_wrap.rs b/tests/source/itemized-blocks/no_wrap.rs
index a7b6a10..e5699e7 100644
--- a/tests/source/itemized-blocks/no_wrap.rs
+++ b/tests/source/itemized-blocks/no_wrap.rs
@@ -1,7 +1,7 @@
// rustfmt-normalize_comments: true
// rustfmt-format_code_in_doc_comments: true
-//! This is a list:
+//! This is an itemized markdown list (see also issue #3224):
//! * Outer
//! * Outer
//! * Inner
@@ -13,6 +13,40 @@
//! - when the log level is info, the level name is green and the rest of the line is white
//! - when the log level is debug, the whole line is white
//! - when the log level is trace, the whole line is gray ("bright black")
+//!
+//! This is a numbered markdown list (see also issue #5416):
+//! 1. Long long long long long long long long long long long long long long long long long line
+//! 2. Another very long long long long long long long long long long long long long long long line
+//! 3. Nested list
+//! 1. Long long long long long long long long long long long long long long long long line
+//! 2. Another very long long long long long long long long long long long long long long line
+//! 4. Last item
+//!
+//! Using the ')' instead of '.' character after the number:
+//! 1) Long long long long long long long long long long long long long long long long long line
+//! 2) Another very long long long long long long long long long long long long long long long line
+//!
+//! Deep list that mixes various bullet and number formats:
+//! 1. First level with a long long long long long long long long long long long long long long
+//! long long long line
+//! 2. First level with another very long long long long long long long long long long long long
+//! long long long line
+//! * Second level with a long long long long long long long long long long long long long
+//! long long long line
+//! * Second level with another very long long long long long long long long long long long
+//! long long long line
+//! 1) Third level with a long long long long long long long long long long long long long
+//! long long long line
+//! 2) Third level with another very long long long long long long long long long long
+//! long long long long line
+//! - Forth level with a long long long long long long long long long long long long
+//! long long long long line
+//! - Forth level with another very long long long long long long long long long long
+//! long long long long line
+//! 3) One more item at the third level
+//! 4) Last item of the third level
+//! * Last item of second level
+//! 3. Last item of first level
/// All the parameters ***except for `from_theater`*** should be inserted as sent by the remote
/// theater, i.e., as passed to [`Theater::send`] on the remote actor:
diff --git a/tests/source/itemized-blocks/wrap.rs b/tests/source/itemized-blocks/wrap.rs
index 955cc69..768461a 100644
--- a/tests/source/itemized-blocks/wrap.rs
+++ b/tests/source/itemized-blocks/wrap.rs
@@ -2,7 +2,7 @@
// rustfmt-format_code_in_doc_comments: true
// rustfmt-max_width: 50
-//! This is a list:
+//! This is an itemized markdown list (see also issue #3224):
//! * Outer
//! * Outer
//! * Inner
@@ -14,6 +14,40 @@
//! - when the log level is info, the level name is green and the rest of the line is white
//! - when the log level is debug, the whole line is white
//! - when the log level is trace, the whole line is gray ("bright black")
+//!
+//! This is a numbered markdown list (see also issue #5416):
+//! 1. Long long long long long long long long long long long long long long long long long line
+//! 2. Another very long long long long long long long long long long long long long long long line
+//! 3. Nested list
+//! 1. Long long long long long long long long long long long long long long long long line
+//! 2. Another very long long long long long long long long long long long long long long line
+//! 4. Last item
+//!
+//! Using the ')' instead of '.' character after the number:
+//! 1) Long long long long long long long long long long long long long long long long long line
+//! 2) Another very long long long long long long long long long long long long long long long line
+//!
+//! Deep list that mixes various bullet and number formats:
+//! 1. First level with a long long long long long long long long long long long long long long
+//! long long long line
+//! 2. First level with another very long long long long long long long long long long long long
+//! long long long line
+//! * Second level with a long long long long long long long long long long long long long
+//! long long long line
+//! * Second level with another very long long long long long long long long long long long
+//! long long long line
+//! 1) Third level with a long long long long long long long long long long long long long
+//! long long long line
+//! 2) Third level with another very long long long long long long long long long long
+//! long long long long line
+//! - Forth level with a long long long long long long long long long long long long
+//! long long long long line
+//! - Forth level with another very long long long long long long long long long long
+//! long long long long line
+//! 3) One more item at the third level
+//! 4) Last item of the third level
+//! * Last item of second level
+//! 3. Last item of first level
// This example shows how to configure fern to output really nicely colored logs
// - when the log level is error, the whole line is red
diff --git a/tests/target/itemized-blocks/no_wrap.rs b/tests/target/itemized-blocks/no_wrap.rs
index de88563..86818b4 100644
--- a/tests/target/itemized-blocks/no_wrap.rs
+++ b/tests/target/itemized-blocks/no_wrap.rs
@@ -1,7 +1,7 @@
// rustfmt-normalize_comments: true
// rustfmt-format_code_in_doc_comments: true
-//! This is a list:
+//! This is an itemized markdown list (see also issue #3224):
//! * Outer
//! * Outer
//! * Inner
@@ -13,6 +13,40 @@
//! - when the log level is info, the level name is green and the rest of the line is white
//! - when the log level is debug, the whole line is white
//! - when the log level is trace, the whole line is gray ("bright black")
+//!
+//! This is a numbered markdown list (see also issue #5416):
+//! 1. Long long long long long long long long long long long long long long long long long line
+//! 2. Another very long long long long long long long long long long long long long long long line
+//! 3. Nested list
+//! 1. Long long long long long long long long long long long long long long long long line
+//! 2. Another very long long long long long long long long long long long long long long line
+//! 4. Last item
+//!
+//! Using the ')' instead of '.' character after the number:
+//! 1) Long long long long long long long long long long long long long long long long long line
+//! 2) Another very long long long long long long long long long long long long long long long line
+//!
+//! Deep list that mixes various bullet and number formats:
+//! 1. First level with a long long long long long long long long long long long long long long
+//! long long long line
+//! 2. First level with another very long long long long long long long long long long long long
+//! long long long line
+//! * Second level with a long long long long long long long long long long long long long
+//! long long long line
+//! * Second level with another very long long long long long long long long long long long
+//! long long long line
+//! 1) Third level with a long long long long long long long long long long long long long
+//! long long long line
+//! 2) Third level with another very long long long long long long long long long long
+//! long long long long line
+//! - Forth level with a long long long long long long long long long long long long
+//! long long long long line
+//! - Forth level with another very long long long long long long long long long long
+//! long long long long line
+//! 3) One more item at the third level
+//! 4) Last item of the third level
+//! * Last item of second level
+//! 3. Last item of first level
/// All the parameters ***except for `from_theater`*** should be inserted as sent by the remote
/// theater, i.e., as passed to [`Theater::send`] on the remote actor:
diff --git a/tests/target/itemized-blocks/wrap.rs b/tests/target/itemized-blocks/wrap.rs
index a490730..4826590 100644
--- a/tests/target/itemized-blocks/wrap.rs
+++ b/tests/target/itemized-blocks/wrap.rs
@@ -2,7 +2,8 @@
// rustfmt-format_code_in_doc_comments: true
// rustfmt-max_width: 50
-//! This is a list:
+//! This is an itemized markdown list (see also
+//! issue #3224):
//! * Outer
//! * Outer
//! * Inner
@@ -23,6 +24,65 @@
//! is white
//! - when the log level is trace, the whole line
//! is gray ("bright black")
+//!
+//! This is a numbered markdown list (see also
+//! issue #5416):
+//! 1. Long long long long long long long long
+//! long long long long long long long long
+//! long line
+//! 2. Another very long long long long long long
+//! long long long long long long long long
+//! long line
+//! 3. Nested list
+//! 1. Long long long long long long long long
+//! long long long long long long long long
+//! line
+//! 2. Another very long long long long long
+//! long long long long long long long long
+//! long line
+//! 4. Last item
+//!
+//! Using the ')' instead of '.' character after
+//! the number:
+//! 1) Long long long long long long long long
+//! long long long long long long long long
+//! long line
+//! 2) Another very long long long long long long
+//! long long long long long long long long
+//! long line
+//!
+//! Deep list that mixes various bullet and number
+//! formats:
+//! 1. First level with a long long long long long
+//! long long long long long long long long
+//! long long long long line
+//! 2. First level with another very long long
+//! long long long long long long long long
+//! long long long long long line
+//! * Second level with a long long long long
+//! long long long long long long long long
+//! long long long long line
+//! * Second level with another very long long
+//! long long long long long long long long
+//! long long long long line
+//! 1) Third level with a long long long
+//! long long long long long long long
+//! long long long long long long line
+//! 2) Third level with another very long
+//! long long long long long long long
+//! long long long long long long line
+//! - Forth level with a long long
+//! long long long long long long
+//! long long long long long long
+//! long long line
+//! - Forth level with another very
+//! long long long long long long
+//! long long long long long long
+//! long long line
+//! 3) One more item at the third level
+//! 4) Last item of the third level
+//! * Last item of second level
+//! 3. Last item of first level
// This example shows how to configure fern to
// output really nicely colored logs
