Skylint: set module docstring location to just the first line

Previously, the location of the warning was the whole file. Now it is 1:1-2:1. This doesn't make sense if the file is empty but I think it's good enough since that's an edge case.

RELNOTES: none
PiperOrigin-RevId: 171942703

2 files changed, 3 insertions, 2 deletions

diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/DocstringChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/DocstringChecker.java
index 48ba98acf5..c19a68b58f 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/DocstringChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/DocstringChecker.java
@@ -48,7 +48,8 @@ public class DocstringChecker extends SyntaxTreeVisitor {
     if (moduleDocstring == null) {
       // The reported location starts on the first line since that's where the docstring is expected
       Location start = new Location(1, 1);
-      Location end = Location.from(node.getLocation().getEndLineAndColumn());
+      // This location is invalid if the file is empty but this edge case is not worth the trouble.
+      Location end = new Location(2, 1);
       LocationRange range = new LocationRange(start, end);
       issues.add(new Issue("file has no module docstring", range));
     } else {
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DocstringCheckerTests.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DocstringCheckerTests.java
index 3f28066876..8b399ccd34 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DocstringCheckerTests.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DocstringCheckerTests.java
@@ -40,7 +40,7 @@ public class DocstringCheckerTests {
     String errorMessage =
         findIssues("# no module docstring", "def function():", "  pass # no function docstring")
             .toString();
-    Truth.assertThat(errorMessage).contains("1:1-3:30: file has no module docstring");
+    Truth.assertThat(errorMessage).contains("1:1-2:1: file has no module docstring");
     Truth.assertThat(errorMessage).contains("2:1-3:30: function 'function' has no docstring");
   }