Fixing a number of bugs with collection expressions

closes #1049
closes #1047

Src/CSharpier.Tests/FormattingTests/TestFiles/cs/CollectionExpressions.test

@@ -18,3 +18,55 @@ int[][] d =
  [4, 5, 6],
  [7, 8, 9]
 ];
+
+var a = new A { B = [1, 2, 3] };
+
+List<string> items =
+[
+ // My item
+ "Hello",
+];
+
+items.AddRange(
+ [
+ "More really long words",
+ "which span multiple lines",
+ "are added here",
+ "and something bad",
+ "happens"
+ ]
+);
+
+class MyClass
+{
+ private readonly List<string> _items;
+
+ public MyClass()
+ {
+ _items = [];
+ _items ??= [];
+ }
+
+ public TheoryData<string[]> ArgsData =>
+ [
+ [],
+ [ArgConstants.UseProgramMain],
+ [ArgConstants.GlobalInteractivity, ArgConstants.WebAssemblyInteractivity],
+ [
+ ArgConstants.NoInteractivity,
+ ArgConstants.UseProgramMain,
+ ArgConstants.NoHttps,
+ ArgConstants.Empty
+ ],
+ ];
+
+ public ReadOnlySpan<HttpMethod> Methods() =>
+ [
+ HttpMethod.None,
+ HttpMethod.Put,
+ HttpMethod.Post,
+ HttpMethod.Patch,
+ HttpMethod.None,
+ HttpMethod.Connect,
+ ];
+}

Src/CSharpier/SyntaxPrinter/SyntaxNodePrinters/CollectionExpression.cs

@@ -5,12 +5,15 @@ internal static class CollectionExpression
  public static Doc Print(CollectionExpressionSyntax node, FormattingContext context)
  {
  Doc separator = node.Parent
- is AssignmentExpressionSyntax
+ is ArgumentSyntax
+ or ArrowExpressionClauseSyntax
+ or ExpressionElementSyntax
+ or AssignmentExpressionSyntax { Parent: not ObjectCreationExpressionSyntax }
  or EqualsValueClauseSyntax
  {
  Parent: not (PropertyDeclarationSyntax or VariableDeclaratorSyntax)
  }
- ? Doc.Line
+ ? Doc.Null
  : Doc.IfBreak(Doc.Line, Doc.Null);
 
  var alwaysBreak =

Src/CSharpier/SyntaxPrinter/SyntaxNodePrinters/ExpressionElement.cs

@@ -0,0 +1,9 @@
+namespace CSharpier.SyntaxPrinter.SyntaxNodePrinters;
+
+internal static class ExpressionElement
+{
+ public static Doc Print(ExpressionElementSyntax node, FormattingContext context)
+ {
+ return Node.Print(node.Expression, context);
+ }
+}