feat: add alignComments option (fix #13)

docs/src/SUMMARY.md

@@ -13,6 +13,7 @@
   - [omitNumberLeadingZero](./config/omit-number-leading-zero.md)
   - [trailingComma](./config/trailing-comma.md)
   - [formatComments](./config/format-comments.md)
+  - [alignComments](./config/align-comments.md)
   - [linebreakInPseudoParens](./config/linebreak-in-pseudo-parens.md)
   - [declarationOrder](./config/declaration-order.md)
   - [singleLineBlockThreshold](./config/single-line-block-threshold.md)

docs/src/config/align-comments.md

@@ -0,0 +1,61 @@
+# `alignComments`
+
+Control whether to tweak multi-line comments indentation.
+
+Default option value is `true`.
+
+## Example for `false`
+
+[Playground](https://malva-play.vercel.app/?code=H4sIAAAAAAAAA0tUqOZSAAJ9LYXk%2FNzc1LwShZzMvFQFQ7AoEKCIGmEVNQaLaumDqZLUihLdlNTk%2FKLEksz8PCuFvPy8VGuuWgAzUTX%2BaQAAAA%3D%3D&config=H4sIAAAAAAAAA6vmUlBQSszJTM9zzs%2FNTc0rKVayUkhLzClO5aoFAIntfVEcAAAA&syntax=css)
+
+When formatting the 4-space indented CSS into 2-space indented CSS:
+
+```css
+a {
+    /* comment line 1
+       comment line 2
+       comment line 3
+    */
+    text-decoration: none;
+}
+```
+
+will be formatted as:
+
+```css
+a {
+  /* comment line 1
+       comment line 2
+       comment line 3
+    */
+  text-decoration: none;
+}
+```
+
+## Example for `true`
+
+[Playground](https://malva-play.vercel.app/?code=H4sIAAAAAAAAA0tUqOZSAAJ9LYXk%2FNzc1LwShZzMvFQFQ7AoEKCIGmEVNQaLaumDqZLUihLdlNTk%2FKLEksz8PCuFvPy8VGuuWgAzUTX%2BaQAAAA%3D%3D&config=H4sIAAAAAAAAA6vmUlBQSszJTM9zzs%2FNTc0rKVayUigpKk3lqgUAiNln3BsAAAA%3D&syntax=css)
+
+When formatting the 4-space indented CSS into 2-space indented CSS:
+
+```css
+a {
+    /* comment line 1
+       comment line 2
+       comment line 3
+    */
+    text-decoration: none;
+}
+```
+
+will be formatted as:
+
+```css
+a {
+  /* comment line 1
+     comment line 2
+     comment line 3
+  */
+  text-decoration: none;
+}
+```

dprint_plugin/deployment/schema.json

@@ -138,6 +138,11 @@
       "type": "boolean",
       "default": false
     },
+    "alignComments": {
+      "description": "Control whether to tweak multi-line comments indentation.",
+      "type": "boolean",
+      "default": true
+    },
     "linebreakInPseudoParens": {
       "description": "Control whether line break should be inserted in pseudo class/element parens or not if current line is too long.",
       "type": "boolean",

dprint_plugin/src/config.rs

@@ -146,6 +146,7 @@ pub(crate) fn resolve_config(
             trailing_comma: get_value(&mut config, "trailingComma", false, &mut diagnostics),
             format_comments: get_nullable_value(&mut config, "formatComments", &mut diagnostics)
                 .unwrap_or_else(|| get_value(&mut config, "padComments", false, &mut diagnostics)),
+            align_comments: get_value(&mut config, "alignComments", true, &mut diagnostics),
             linebreak_in_pseudo_parens: get_value(
                 &mut config,
                 "linebreakInPseudoParens",

malva/src/config.rs

@@ -119,6 +119,9 @@ pub struct LanguageOptions {
     /// See [`formatComments`](https://malva.netlify.app/config/format-comments.html)
     pub format_comments: bool,
 
+    #[cfg_attr(feature = "config_serde", serde(alias = "alignComments"))]
+    pub align_comments: bool,
+
     #[cfg_attr(
         feature = "config_serde",
         serde(alias = "linebreakInPseudoParens", alias = "lineBreakInPseudoParens")
@@ -266,6 +269,7 @@ impl Default for LanguageOptions {
             omit_number_leading_zero: false,
             trailing_comma: false,
             format_comments: false,
+            align_comments: true,
             linebreak_in_pseudo_parens: false,
             declaration_order: None,
             single_line_block_threshold: None,

malva/src/doc_gen/comment.rs

@@ -35,6 +35,8 @@ pub(crate) fn format_comment<'s>(comment: &Comment<'s>, ctx: &Ctx<'_, 's>) -> Do
                 docs.extend(
                     lines.map(|line| Doc::hard_line().append(Doc::text(line.trim_start()))),
                 );
+            } else if ctx.options.align_comments {
+                docs.append(&mut reflow(comment, ctx));
             } else {
                 docs.extend(itertools::intersperse(
                     lines.map(Doc::text),
@@ -76,3 +78,30 @@ pub(crate) fn format_comment<'s>(comment: &Comment<'s>, ctx: &Ctx<'_, 's>) -> Do
         }
     }
 }
+
+pub(super) fn reflow<'s>(comment: &Comment<'s>, ctx: &Ctx<'_, 's>) -> Vec<Doc<'s>> {
+    let col = ctx
+        .line_bounds
+        .get_line_col(comment.span.start)
+        .1
+        .saturating_sub(1);
+    let mut docs = Vec::with_capacity(2);
+    let mut lines = comment.content.split('\n').enumerate().peekable();
+    while let Some((i, line)) = lines.next() {
+        let s = line.strip_suffix('\r').unwrap_or(line);
+        let s = if s.starts_with([' ', '\t']) && i > 0 {
+            s.get(col..).unwrap_or(s)
+        } else {
+            s
+        };
+        if i > 0 {
+            if s.trim().is_empty() && lines.peek().is_some() {
+                docs.push(Doc::empty_line());
+            } else {
+                docs.push(Doc::hard_line());
+            }
+        }
+        docs.push(Doc::text(s));
+    }
+    docs
+}

malva/src/line_bounds.rs

@@ -24,7 +24,7 @@ impl LineBounds {
 
     pub(crate) fn get_line_col(&self, pos: usize) -> (usize, usize) {
         let line = self.get_line_at(pos);
-        (line, pos - self.0[line - 1])
+        (line, pos - self.0[line.saturating_sub(1)])
     }
 
     fn get_line_at(&self, pos: usize) -> usize {

malva/tests/fmt/css/align-comments/disabled.css

@@ -0,0 +1,8 @@
+/*cfg alignComments = false */
+a {
+    /* comment line 1
+       comment line 2
+       comment line 3
+    */
+    text-decoration: none;
+}

malva/tests/fmt/css/align-comments/disabled.snap

@@ -0,0 +1,11 @@
+---
+source: malva/tests/fmt.rs
+---
+/*cfg alignComments = false */
+a {
+  /* comment line 1
+       comment line 2
+       comment line 3
+    */
+  text-decoration: none;
+}

malva/tests/fmt/css/align-comments/enabled.css

@@ -0,0 +1,7 @@
+a {
+    /* comment line 1
+       comment line 2
+       comment line 3
+    */
+    text-decoration: none;
+}

malva/tests/fmt/css/align-comments/enabled.snap

@@ -0,0 +1,10 @@
+---
+source: malva/tests/fmt.rs
+---
+a {
+  /* comment line 1
+     comment line 2
+     comment line 3
+  */
+  text-decoration: none;
+}