Work around flow analysis bug (#59)
Flow analysis currently has a bug preventing for-each loop variables
from being properly promoted in the presence of closures
(https://github.com/dart-lang/sdk/issues/43136); as a result of this
bug the source_span package had two non-null assertions that ought to
have been unnecessary.
I'm preparing a fix for that bug, however if I land it as is, it will
cause the front end to emit errors saying "Operand of null-aware
operation '!' has type '_Highlight' which excludes null"; this in turn
will cause SDK bot breakages (since source_span is imported into the
SDK repo).
So, in order to land the fix, we need to first update the source_span
package to work around the bug; this change does that by allocating a
temporary variable (which *is* promoted correctly).
Once the fix for https://github.com/dart-lang/sdk/issues/43136 lands,
I will make a follow-up change that deletes the temporary variable.
diff --git a/lib/src/highlighter.dart b/lib/src/highlighter.dart
index d61ff9f..1c39185 100644
--- a/lib/src/highlighter.dart
+++ b/lib/src/highlighter.dart
@@ -292,7 +292,9 @@
? _primaryColor
: _secondaryColor;
var foundCurrent = false;
- for (var highlight in highlightsByColumn) {
+ for (var tmp in highlightsByColumn) {
+ // Work around https://github.com/dart-lang/sdk/issues/43136
+ final highlight = tmp;
final startLine = highlight?.span.start.line;
final endLine = highlight?.span.end.line;
if (current != null && highlight == current) {
@@ -326,9 +328,9 @@
}, color: openedOnThisLineColor);
openedOnThisLine = true;
openedOnThisLineColor ??=
- highlight!.isPrimary ? _primaryColor : _secondaryColor;
+ highlight.isPrimary ? _primaryColor : _secondaryColor;
} else if (endLine == line.number &&
- highlight!.span.end.column == line.text.length) {
+ highlight.span.end.column == line.text.length) {
_buffer.write(highlight.label == null
? glyph.glyphOrAscii('└', '\\')
: vertical);
