public void DeclaringTuples_WithMistmatchedTuplePropertyNames_IssuesWarning()
{
CompilerAssert.StatementsFailCompilation(
@"
(string DirectoryName, string FileName, string Extension) pathData =
(AltDirectoryName1: @""\\test\unc\path\to"", FileName: ""something"", Extension: "".ext"");
pathData = (AltDirectoryName2: @""\\test\unc\path\to"",
FileName: ""something"", Extension:"".ext"");
pathData.GetType();
",
@"Warning CS8123: The tuple element name 'AltDirectoryName1' is ignored because a different name is specified by the target type '(string DirectoryName, string FileName, string Extension)'.",
"Warning CS8123: The tuple element name 'AltDirectoryName2' is ignored because a different name is specified by the target type '(string DirectoryName, string FileName, string Extension)'."
);
CompilerAssert.StatementsFailCompilation(
@"
(string, string, string) pathData =
(DirectoryName: @""\\test\unc\path\to"",
FileName: ""something"",
Extension: "".ext"");
pathData.GetType();
",
"Warning CS8123: The tuple element name 'DirectoryName' is ignored because a different name is specified by the target type '(string, string, string)'.",
"Warning CS8123: The tuple element name 'Extension' is ignored because a different name is specified by the target type '(string, string, string)'.",
"Warning CS8123: The tuple element name 'FileName' is ignored because a different name is specified by the target type '(string, string, string)'.");
}
public void Deconstruct_AssignmentToValueTypeIsNotSupported()
{
string[] expectedErrors =
{
"Error CS0029: Cannot implicitly convert type 'CSharp7.PathInfo' to '(string DirectoryName, string FileName, string Extension)'"
};
CompilerAssert.StatementsFailCompilation(
@"
PathInfo pathInfo = new PathInfo(
@""\\test\unc\path\to\something.ext"");
// E.g. 4: Deconstructing declaration and assignment to a ValueTuple
(string DirectoryName, string FileName, string Extension) path = pathInfo;
",
expectedErrors);
}
public void Deconstruct_GivenSingleOutOParameter_FailsCompilation()
{
string[] expectedErrors =
{
"Error CS1002: ; expected",
"Error CS1002: ; expected",
"Error CS1513: } expected",
"Error CS1525: Invalid expression term '='",
"Error CS0119: 'FileInfo' is a type, which is not valid in the given context",
"Error CS0119: 'FileInfo' is a type, which is not valid in the given context",
"Error CS0103: The name 'path' does not exist in the current context",
"Error CS1026: ) expected"
};
CompilerAssert.StatementsFailCompilation(
@"
PathInfo pathInfo = new PathInfo(
@""\\test\unc\path\to\something.ext"");
(FileInfo path) = pathInfo;
",
expectedErrors);
}
public void ByRefCompileErrors()
{
void AssertStatementsFailCompilation(string body, params string[] expectedText)
{
string MethodScaffolding = $@"#pragma warning disable CS0168 // Disable variable declared but never used.
{body}
#pragma warning restore CS0168";
CompilerAssert.StatementsFailCompilation(MethodScaffolding, expectedText);
}
AssertStatementsFailCompilation("ref int number;",
"Error CS8174: A declaration of a by-reference variable must have an initializer");
AssertStatementsFailCompilation("ref int number = ref 42;",
"Error CS1510: A ref or out value must be an assignable variable");
AssertStatementsFailCompilation("ref int number = null;",
"Error CS1510: A ref or out value must be an assignable variable",
"Error CS8172: Cannot initialize a by-reference variable with a value");
AssertStatementsFailCompilation("ref string number = \"Inigo Montoya\";",
"Error CS1510: A ref or out value must be an assignable variable",
"Error CS8172: Cannot initialize a by-reference variable with a value");
AssertStatementsFailCompilation(
@"Guid guid = Guid.NewGuid();
ref object obj = ref guid;",
"Error CS8173: The expression must be of type 'object' because it is being assigned by reference");
AssertStatementsFailCompilation(
@"Guid guid = Guid.NewGuid();
ref object obj = ref guid;",
"Error CS8173: The expression must be of type 'object' because it is being assigned by reference");
AssertStatementsFailCompilation(
@"IEnumerable<ref int> numbers;",
"Error CS1073: Unexpected token 'ref'");
//AssertStatementsFailCompilation(
// @"ref int[] numbers; ",
// "Error CS1073: Unexpected token 'ref'");
}