JS: Add support for YAML comments.

Author: MathiasVP

actions/ql/lib/codeql/Locations.qll

@@ -23,6 +23,11 @@ newtype TLocation =
       e.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
     )
     or
+    exists(File file |
+      yamlCommentHasLocationInfo(_, file, startline, startcolumn, endline, endcolumn) and
+      file.getAbsolutePath() = filepath
+    )
+    or
     filepath = "" and startline = 0 and startcolumn = 0 and endline = 0 and endcolumn = 0
   }
 

actions/ql/lib/codeql/actions/ast/internal/Ast.qll

@@ -1920,3 +1920,39 @@ private YamlMappingLikeNode resolveMatrixAccessPath(
     else result = resolveMatrixAccessPath(newRoot, rest)
   )
 }
+
+/** Holds if `c` has location information `(file, startline, startcolumn, endline, endcolumn)`. */
+predicate yamlCommentHasLocationInfo(
+  @yaml_comment c, File file, int startline, int startcolumn, int endline, int endcolumn
+) {
+  exists(@location l |
+    hasLocation(c, l) and
+    locations_default(l, file, startline, startcolumn, endline, endcolumn)
+  )
+}
+
+/**
+ * A comment.
+ *
+ * Example:
+ *
+ * ```
+ * # here is a comment
+ * ```
+ */
+class Comment extends @yaml_comment {
+  /** Gets the text of this comment, not including delimiters. */
+  string getText() { comments(this, _, _, result, _) }
+
+  /** Gets the location of this comment. */
+  Location getLocation() {
+    exists(File file, string filepath, int startline, int startcolumn, int endline, int endcolumn |
+      yamlCommentHasLocationInfo(this, file, startline, startcolumn, endline, endcolumn) and
+      filepath = file.getAbsolutePath() and
+      result.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+    )
+  }
+
+  /** Gets a string representation of this comment. */
+  string toString() { comments(this, _, _, _, result) }
+}

javascript/ql/lib/semmle/javascript/Comments.qll

@@ -5,7 +5,7 @@ module;
 import javascript
 
 /**
- * A JavaScript source-code comment.
+ * A JavaScript or YAML source-code comment.
  *
  * Examples:
  *
@@ -14,6 +14,7 @@ import javascript
  * /* a block
  *   comment *&#47
  * <!-- an HTML line comment
+ * # a YAML line comment
  * </pre>
  */
 class Comment extends @comment, Locatable {
@@ -44,13 +45,14 @@ class Comment extends @comment, Locatable {
 }
 
 /**
- * A line comment, that is, either an HTML comment or a `//` comment.
+ * A line comment, that is, an HTML comment, a `//` comment, or a YAML comment.
  *
  * Examples:
  *
  * <pre>
  * // a line comment
  * &lt;!-- an HTML line comment
+ * # a YAML line comment
  * </pre>
  */
 class LineComment extends @line_comment, Comment { }
@@ -100,6 +102,17 @@ class HtmlCommentEnd extends @htmlcommentend, HtmlLineComment { }
  */
 class SlashSlashComment extends @slashslash_comment, LineComment { }
 
+/**
+ * A YAML line comment.
+ *
+ * Example:
+ *
+ * ```
+ * # a line comment
+ * ```
+ */
+class YamlComment extends @yaml_comment, LineComment { }
+
 /**
  * A block comment (which may be a JSDoc comment).
  *

javascript/ql/lib/semmlecode.javascript.dbscheme

@@ -800,10 +800,11 @@ case @comment.kind of
 | 1 = @slashstar_comment
 | 2 = @doc_comment
 | 3 = @html_comment_start
-| 4 = @htmlcommentend;
+| 4 = @htmlcommentend
+| 5 = @yaml_comment;
 
 @html_comment = @html_comment_start | @htmlcommentend;
-@line_comment = @slashslash_comment | @html_comment;
+@line_comment = @slashslash_comment | @html_comment | @yaml_comment;
 @block_comment = @slashstar_comment | @doc_comment;
 
 // source lines