Merge branch 'master' into better-empty-spread-collection
# Conflicts:
# CHANGELOG.md
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 31da7f3..4234f1b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
* Format `?` in types.
* Format the `late` modifier.
* Format the `required` modifier.
+* Better formatting of empty spread collections (#831).
# 1.2.10
diff --git a/lib/src/source_visitor.dart b/lib/src/source_visitor.dart
index 54e2451..35b0396 100644
--- a/lib/src/source_visitor.dart
+++ b/lib/src/source_visitor.dart
@@ -457,8 +457,7 @@
// Treat empty blocks specially. In most cases, they are not allowed to
// split. However, an empty block as the then statement of an if with an
// else is always split.
- if (node.statements.isEmpty &&
- node.rightBracket.precedingComments == null) {
+ if (_isEmptyCollection(node.statements, node.rightBracket)) {
token(node.leftBracket);
// Force a split when used as the then body of an if with an else:
@@ -2763,7 +2762,7 @@
}
// Don't allow splitting in an empty collection.
- if (elements.isEmpty && rightBracket.precedingComments == null) {
+ if (_isEmptyCollection(elements, rightBracket)) {
token(leftBracket);
token(rightBracket);
return;
@@ -3000,8 +2999,16 @@
bool _isSpreadCollection(AstNode node) =>
_findSpreadCollectionBracket(node) != null;
- /// If [node] is a spread of a collection literal, then this returns the
- /// token for the opening bracket of the collection, as in:
+ /// Whether the collection literal or block containing [nodes] and
+ /// terminated by [rightBracket] is empty or not.
+ ///
+ /// An empty collection must have no elements or comments inside. Collections
+ /// like that are treated specially because they cannot be split inside.
+ bool _isEmptyCollection(Iterable<AstNode> nodes, Token rightBracket) =>
+ nodes.isEmpty && rightBracket.precedingComments == null;
+
+ /// If [node] is a spread of a non-empty collection literal, then this
+ /// returns the token for the opening bracket of the collection, as in:
///
/// [ ...[a, list] ]
/// // ^
@@ -3010,8 +3017,15 @@
Token _findSpreadCollectionBracket(AstNode node) {
if (node is SpreadElement) {
var expression = node.expression;
- if (expression is ListLiteral) return expression.leftBracket;
- if (expression is SetOrMapLiteral) return expression.leftBracket;
+ if (expression is ListLiteral) {
+ if (!_isEmptyCollection(expression.elements, expression.rightBracket)) {
+ return expression.leftBracket;
+ }
+ } else if (expression is SetOrMapLiteral) {
+ if (!_isEmptyCollection(expression.elements, expression.rightBracket)) {
+ return expression.leftBracket;
+ }
+ }
}
return null;
diff --git a/test/regression/0800/0831.unit b/test/regression/0800/0831.unit
new file mode 100644
index 0000000..f4b754a
--- /dev/null
+++ b/test/regression/0800/0831.unit
@@ -0,0 +1,17 @@
+>>>
+foo() {
+ final bar = [
+ if (longVariableName == 'do nothing but be long') ...[] else if (longVariableName ==
+ 'show the welcome message')
+ 'Hello'
+ ];
+}
+<<<
+foo() {
+ final bar = [
+ if (longVariableName == 'do nothing but be long')
+ ...[]
+ else if (longVariableName == 'show the welcome message')
+ 'Hello'
+ ];
+}
\ No newline at end of file
diff --git a/test/splitting/list_collection_if.stmt b/test/splitting/list_collection_if.stmt
index 36e44c2..00d9cb3 100644
--- a/test/splitting/list_collection_if.stmt
+++ b/test/splitting/list_collection_if.stmt
@@ -313,4 +313,100 @@
else ...{
h
}
+];
+>>> empty then spread not treated like block
+var list = [
+ if (condition) ...[] else ...[a,]
+];
+<<<
+var list = [
+ if (condition)
+ ...[]
+ else ...[
+ a,
+ ]
+];
+>>> empty else spread not treated like block
+var list = [
+ if (condition) ...[a,] else ...[]
+];
+<<<
+var list = [
+ if (condition) ...[
+ a,
+ ] else
+ ...[]
+];
+>>> empty then spread does not split
+var list = [
+ if (condition) ...[] else veryLongIdentifier
+];
+<<<
+var list = [
+ if (condition)
+ ...[]
+ else
+ veryLongIdentifier
+];
+>>> empty else spread does not split
+var list = [
+ if (condition) veryLongIdentifier else ...[]
+];
+<<<
+var list = [
+ if (condition)
+ veryLongIdentifier
+ else
+ ...[]
+];
+>>> empty then spread with comment treated like block
+var list = [
+ if (condition) ...[// c
+ ] else ...[a,]
+];
+<<<
+var list = [
+ if (condition) ...[
+ // c
+ ] else ...[
+ a,
+ ]
+];
+>>> empty else spread with comment treated like block
+var list = [
+ if (condition) ...[a,] else ...[// c
+ ]
+];
+<<<
+var list = [
+ if (condition) ...[
+ a,
+ ] else ...[
+ // c
+ ]
+];
+>>> empty then spread with comment splits
+var list = [
+ if (condition) ...[// c
+ ] else veryLongIdentifier
+];
+<<<
+var list = [
+ if (condition) ...[
+ // c
+ ] else
+ veryLongIdentifier
+];
+>>> empty else spread with comment splits
+var list = [
+ if (condition) veryLongIdentifier else ...[// c
+ ]
+];
+<<<
+var list = [
+ if (condition)
+ veryLongIdentifier
+ else ...[
+ // c
+ ]
];
\ No newline at end of file
