Fixed inline comment on first body line

src/Lexer.mjs

@@ -37,6 +37,11 @@ export const Value = createToken({
   line_breaks: true,
   pop_mode: true,
 });
+export const CommentStartNewline = createToken({
+  name: "CommentStartNewline",
+  pattern: '\n#',
+  push_mode: "comment_mode",
+});
 export const CommentStart = createToken({
   name: "CommentStart",
   pattern: '#',
@@ -56,6 +61,7 @@ export const WhiteSpace = createToken({
 
 export const tokens = [
   CommentStart,
+  CommentStartNewline,
   Value,
   Comment,
   SectionHeading,
@@ -67,6 +73,7 @@ export default new Lexer({
   defaultMode: "line_mode",
   modes: {
     line_mode: [
+      CommentStartNewline,
       CommentStart,
       SectionHeading,
       Property,

src/Parser.mjs

@@ -4,6 +4,7 @@ import {
   tokens,
   Comment,
   CommentStart,
+  CommentStartNewline,
   Property,
   SectionHeading,
   Value,
@@ -14,6 +15,11 @@ export default class UnitFileParser extends CstParser {
     super(tokens);
     const $ = this;
 
+    $.RULE("commentLine", () => {
+      $.CONSUME(CommentStartNewline);
+      $.CONSUME(Comment);
+    });
+
     $.RULE("comment", () => {
       $.CONSUME(CommentStart);
       $.CONSUME(Comment);
@@ -41,7 +47,7 @@ export default class UnitFileParser extends CstParser {
     $.RULE("sectionStatement", () => {
       $.OR([
         { ALT: () => $.SUBRULE($.propertyStatement) },
-        { ALT: () => $.SUBRULE($.comment) },
+        { ALT: () => $.SUBRULE($.commentLine) },
       ]);
     });
     

src/visitor.mjs

@@ -7,13 +7,21 @@ export default (parser) => {
       this.validateVisitor();
     };
 
-    comment(ctx) {
+    _comment(ctx) {
       return {
         type: "comment",
         value: ctx.Comment.map(({ image }) => image.replace(/^\s/, '').replace(/\s$/, '')).join(''),
       };
     }
 
+    comment(ctx) {
+      return this._comment(ctx);
+    }
+
+    commentLine(ctx) {
+      return this._comment(ctx);
+    }
+
     propertyStatement(ctx) {
       const name = ctx.Property[0].image;
       return {
@@ -25,7 +33,7 @@ export default (parser) => {
     }
 
     sectionStatement(ctx) {
-      const content = ctx.propertyStatement?.[0] || ctx.comment?.[0];
+      const content = ctx.propertyStatement?.[0] || ctx.commentLine?.[0];
       return this.visit(content);
     }
 

test/examples/comments.mjs

@@ -1,7 +1,7 @@
 export const content = `# Outside comment
 [Unit] # Heading comment
-# Inline comment
 Description=Idle manager for Wayland # End of value comment
+# Inline comment
 ExecStart=echo\
   "some string" # End of value comment
 Alias=asdf#Comment Without spaces
@@ -19,13 +19,13 @@ export const result = {
       title: 'Unit',
       titleComment: { type: 'comment', value: 'Heading comment' },
       body: [
-        { type: 'comment', value: 'Inline comment' },
         {
           type: 'setting',
           name: 'Description',
           value: 'Idle manager for Wayland',
           comment: { type: 'comment', value: 'End of value comment' }
         },
+        { type: 'comment', value: 'Inline comment' },
         {
           type: 'setting',
           name: 'ExecStart',
@@ -43,8 +43,10 @@ export const result = {
     {
       type: 'section',
       title: 'Install',
-      titleComment: { type: 'comment', value: 'Comment only in this body' },
-      body: []
+      titleComment: undefined,
+      body: [
+        { type: 'comment', value: 'Comment only in this body' },
+      ]
     }
   ]
 };

test/spec.mjs

@@ -6,7 +6,7 @@ import {
   visitorCreator,
 } from "../src/mod.mjs";
 
-const runTest = (input) => {
+const runTest = (input, result) => {
   const parser = new Parser([], { outputCst: true });
   const lexingresult = Lexer.tokenize(input);
 
@@ -26,7 +26,25 @@ const runTest = (input) => {
   const Visitor = visitorCreator(parser);
   const visitor = new Visitor();
   const ast = visitor.visit(cst);
-  return ast;
+
+  const resultString = JSON.stringify(ast, null, 2);
+  const expectedString = JSON.stringify(result, null, 2);
+  if (resultString !== expectedString) {
+    console.dir(ast, { depth: Infinity });
+    console.dir(lexingresult, { depth: Infinity });
+    throw new Error(`Mismatching result on testcase:
+${input}
+
+=======Result======
+
+${resultString}
+
+=======Expected======
+
+${expectedString}
+
+`);
+  }
 };
 
 (async () => {
@@ -45,35 +63,5 @@ const runTest = (input) => {
   );
 
   const cases = await Promise.all(files.flat().map(file => import(file)));
-
-  const results = cases.map(
-    ({ content, result }) => {
-      const ast = runTest(content);
-      const resultString = JSON.stringify(ast);
-      const expectedString = JSON.stringify(result);
-      if (resultString !== expectedString) {
-        console.dir(ast, { depth: Infinity });
-        throw new Error(`Mismatching result on testcase:
-${content}
-
-=======Result======
-
-${resultString}
-
-=======Expected======
-
-${expectedString}
-
-`);
-      }
-
-      return null;
-    },
-  )
-  .filter(r => r !== null);
-  
-  if (results.length) {
-    results.forEach(err => console.error(err));
-    throw new Error(`${results.length} failed tests`);
-  }
+  const results = cases.forEach(({ content, result }) => runTest(content, result));
 })();