Fix a highlighting bug (#33)
If a span covered a trailing newline and a single additional line, it
went down a code path that resulted in a range error. That code path
has now been fixed.
Closes #32
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a07a0e6..ddb4ff0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+# 1.5.5
+
+* Fix a bug where `FileSpan.highlight()` would crash for spans that covered a
+ trailing newline and a single additional empty line.
+
# 1.5.4
* `FileSpan.highlight()` now properly highlights point spans at the beginning of
diff --git a/lib/src/highlighter.dart b/lib/src/highlighter.dart
index 8a928b3..17a47bc 100644
--- a/lib/src/highlighter.dart
+++ b/lib/src/highlighter.dart
@@ -117,6 +117,10 @@
SourceSpanWithContext span) {
if (!span.context.endsWith("\n")) return span;
+ // If there's a full blank line on the end of [span.context], it's probably
+ // significant, so we shouldn't trim it.
+ if (span.text.endsWith("\n\n")) return span;
+
var context = span.context.substring(0, span.context.length - 1);
var text = span.text;
var start = span.start;
@@ -156,9 +160,13 @@
if (text.isEmpty) return 0;
// The "- 1" here avoids counting the newline itself.
- return text.codeUnitAt(text.length - 1) == $lf
- ? text.length - text.lastIndexOf("\n", text.length - 2) - 1
- : text.length - text.lastIndexOf("\n") - 1;
+ if (text.codeUnitAt(text.length - 1) == $lf) {
+ return text.length == 1
+ ? 0
+ : text.length - text.lastIndexOf("\n", text.length - 2) - 1;
+ } else {
+ return text.length - text.lastIndexOf("\n") - 1;
+ }
}
/// Returns whether [span]'s text runs all the way to the end of its context.
diff --git a/pubspec.yaml b/pubspec.yaml
index a470875..0cb9326 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
name: source_span
-version: 1.5.4
+version: 1.5.5
description: A library for identifying source spans and locations.
author: Dart Team <misc@dartlang.org>
diff --git a/test/highlight_test.dart b/test/highlight_test.dart
index af9cd1b..5fdf622 100644
--- a/test/highlight_test.dart
+++ b/test/highlight_test.dart
@@ -120,6 +120,15 @@
| ^
'"""));
});
+
+ test("on an empty line", () {
+ var file = new SourceFile.fromString("foo\n\nbar");
+ expect(file.location(4).pointSpan().highlight(), equals("""
+ ,
+2 |
+ | ^
+ '"""));
+ });
});
test("highlights a single-line file without a newline", () {
@@ -131,6 +140,15 @@
'"""));
});
+ test("highlights a single empty line", () {
+ expect(new SourceFile.fromString("foo\n\nbar").span(4, 5).highlight(),
+ equals("""
+ ,
+2 |
+ | ^
+ '"""));
+ });
+
group("with a multiline span", () {
test("highlights the middle of the first and last lines", () {
expect(file.span(4, 34).highlight(), equals("""
@@ -278,6 +296,27 @@
2 | \\
'"""));
});
+
+ test("highlights multiple empty lines", () {
+ var file = new SourceFile.fromString("foo\n\n\n\nbar");
+ expect(file.span(4, 7).highlight(), equals("""
+ ,
+2 | /
+3 | |
+4 | \\
+ '"""));
+ });
+
+ // Regression test for #32
+ test("highlights the end of a line and an empty line", () {
+ var file = new SourceFile.fromString("foo\n\n");
+ expect(file.span(3, 5).highlight(), equals("""
+ ,
+1 | foo
+ | ,----^
+2 | \\
+ '"""));
+ });
});
group("prints tabs as spaces", () {
