Fix adjacent block comments corrupted in less (#19573)

Co-authored-by: fisker Cheung <lionkay@gmail.com>

changelog_unreleased/less/19574.md

@@ -0,0 +1,24 @@
+#### Fix adjacent block comments being corrupted (#19574 by @kovsu)
+
+<!-- prettier-ignore -->
+```less
+// Input
+/* a *//* b */
+/* a */* {
+  color: red;
+}
+
+// Prettier stable
+/* a */
+/* b */
+/* a * {
+  color: red;
+}
+
+// Prettier main
+/* a */ /* b */
+/* a */
+* {
+  color: red;
+}
+```

src/language-css/loc.js

@@ -446,14 +446,16 @@ function replaceQuotesInInlineComments(text) {
           continue;
         }
 
-        if (c === "*" && text[i - 1] === "/") {
-          state = "comment-block";
-          continue;
-        }
-
-        if (c === "/" && text[i - 1] === "/") {
-          state = "comment-inline";
-          inlineCommentStartIndex = i - 1;
+        if (c === "/") {
+          const nextCharacter = text[i + 1];
+          if (nextCharacter === "*") {
+            state = "comment-block";
+            i++;
+          } else if (nextCharacter === "/") {
+            state = "comment-inline";
+            inlineCommentStartIndex = i;
+            i++;
+          }
           continue;
         }
 

tests/format/less/comments/__snapshots__/format.test.js.snap

@@ -61,6 +61,26 @@ parsers: ["less"]
 ================================================================================
 `;
 
+exports[`adjacent.less format 1`] = `
+====================================options=====================================
+parsers: ["less"]
+                                                      printWidth: 80 (default) |
+=====================================input======================================
+/* a *//* b */
+/* a */* {
+  color: red;
+}
+
+=====================================output=====================================
+/* a */ /* b */
+/* a */
+* {
+  color: red;
+}
+
+================================================================================
+`;
+
 exports[`between-decl.less format 1`] = `
 ====================================options=====================================
 parsers: ["less"]

tests/format/less/comments/adjacent.less

@@ -0,0 +1,4 @@
+/* a *//* b */
+/* a */* {
+  color: red;
+}

tests/format/less/less-test-suite/__snapshots__/format.test.js.snap

@@ -6302,6 +6302,233 @@ parsers: ["less"]
 ================================================================================
 `;
 
+exports[`snippet: tests-unit/comments/comments.less format 1`] = `
+====================================options=====================================
+parsers: ["less"]
+                                                      printWidth: 80 (default) |
+=====================================input======================================
+// Comprehensive comment handling tests
+/******************\\
+*                  *
+*  Comment Header  *
+*                  *
+\\******************/
+
+/*
+
+    Comment
+
+*/
+
+/*
+ * Comment Test
+ *
+ * - cloudhead (http://cloudhead.net)
+ *
+ */
+
+////////////////
+@var: "content";
+////////////////
+
+/* Colors
+ * ------
+ *   #EDF8FC (background blue)
+ *   #166C89 (darkest blue)
+ *
+ * Text:
+ *   #333 (standard text) // A comment within a comment!
+ *   #1F9EC9 (standard link)
+ *
+ */
+
+/* @group Variables
+------------------- */
+#comments /* boo *//* boo again*/,
+//.commented_out1
+//.commented_out2
+//.commented_out3
+.comments //end of comments1
+//end of comments2
+{
+  /**/ // An empty comment
+  color: red; /* A C-style comment */  /* A C-style comment */
+  background-color: orange; // A little comment
+  font-size: 12px;
+
+  /* lost comment */ content: @var;
+
+  border: 1px solid black;
+
+  // padding & margin //
+  padding: 0; // }{ '"
+  margin: 2em;
+} //
+
+/* commented out
+  #more-comments {
+    color: grey;
+  }
+*/
+
+.selector /* .with */, .lots, /* of */ .comments {
+  color/* survive */ /* me too */: grey, /* blue */ orange;
+  -webkit-border-radius: 2px /* webkit only */;
+  -moz-border-radius: (2px * 4) /* moz only with operation */;
+}
+
+.mixin_def_with_colors(@a: white, // in
+       @b: 1px //put in @b - causes problems! --->
+       ) // the
+       when (@a = white) {
+    .test-rule {
+        color: @b;
+    }
+}
+.mixin_def_with_colors();
+
+// .s when
+//R/2
+
+.sr-only-focusable {
+  clip: auto;
+}
+
+@-webkit-keyframes /* Safari */ hover /* and Chrome */ {
+  0% {
+    color: red;
+  }
+}
+
+#last { color: blue }
+//
+
+/*  *//* { *//*  *//*  *//*  */#div { color:#A33; }/* } */
+
+// line immediately followed
+/*by block */
+@string_w_comment: ~"/* // Not commented out // */";
+#output-block { --comment: @string_w_comment; }
+/*comment on last line*/
+
+=====================================output=====================================
+// Comprehensive comment handling tests
+/******************\\
+*                  *
+*  Comment Header  *
+*                  *
+\\******************/
+
+/*
+
+    Comment
+
+*/
+
+/*
+ * Comment Test
+ *
+ * - cloudhead (http://cloudhead.net)
+ *
+ */
+
+////////////////
+@var: "content";
+////////////////
+
+/* Colors
+ * ------
+ *   #EDF8FC (background blue)
+ *   #166C89 (darkest blue)
+ *
+ * Text:
+ *   #333 (standard text) // A comment within a comment!
+ *   #1F9EC9 (standard link)
+ *
+ */
+
+/* @group Variables
+------------------- */
+#comments /* boo *//* boo again*/,
+//.commented_out1
+//.commented_out2
+//.commented_out3
+.comments //end of comments1
+//end of comments2
+{
+  /**/ // An empty comment
+  color: red; /* A C-style comment */ /* A C-style comment */
+  background-color: orange; // A little comment
+  font-size: 12px;
+
+  /* lost comment */
+  content: @var;
+
+  border: 1px solid black;
+
+  // padding & margin //
+  padding: 0; // }{ '"
+  margin: 2em;
+} //
+
+/* commented out
+  #more-comments {
+    color: grey;
+  }
+*/
+
+.selector /* .with */, .lots, /* of */ .comments {
+  color/* survive */ /* me too */:
+    grey,
+    /* blue */ orange;
+  -webkit-border-radius: 2px /* webkit only */;
+  -moz-border-radius: (2px * 4) /* moz only with operation */;
+}
+
+.mixin_def_with_colors(@a: white, // in
+       @b: 1px //put in @b - causes problems! --->
+       ) // the
+       when (@a = white) {
+  .test-rule {
+    color: @b;
+  }
+}
+.mixin_def_with_colors();
+
+// .s when
+//R/2
+
+.sr-only-focusable {
+  clip: auto;
+}
+
+@-webkit-keyframes /* Safari */ hover /* and Chrome */ {
+  0% {
+    color: red;
+  }
+}
+
+#last {
+  color: blue;
+}
+//
+
+/*  */ /* { */ /*  */ /*  */ /*  */
+#div {
+  color: #a33;
+} /* } */
+
+// line immediately followed
+/*by block */
+@string_w_comment: ~"/* // Not commented out // */";
+#output-block {
+  --comment: @string_w_comment;
+}
+/*comment on last line*/
+
+================================================================================
+`;
+
 exports[`snippet: tests-unit/comments/comments2.less format 1`] = `
 ====================================options=====================================
 parsers: ["less"]

tests/format/less/less-test-suite/format.test.js

@@ -10,11 +10,9 @@ const BUGS = new Set([
   "tests-unit/permissive-parse/permissive-parse.less",
   "tests-unit/parser-property-interp/parser-property-interp.less",
   "tests-unit/mixins-interpolated/mixins-interpolated.less",
-  "tests-unit/import/import/invalid-css.less",
   "tests-unit/functions/functions.less",
   "tests-unit/extract-and-length/extract-and-length.less",
   "tests-unit/css-escapes/css-escapes.less",
-  "tests-unit/comments/comments.less",
 ]);
 /* spell-checker: enable */