Closed
Description
Description
The MacroApplicationError.accessorMacroOnVariableWithMultipleBindings diagnostic error is leaking into all nested variable declarations that have multiple bindings.
For quick reference, here's the invalid usage that merits the error:
@constantOneGetter
var x: Int, y: Int
┬─────────────────
╰─ 🛑 swift-syntax applies macros syntactically and there is no way to represent a variable
declaration with multiple bindings that have accessors syntactically. While the compiler
allows this expansion, swift-syntax cannot represent it and thus disallows it.
Here are two cases where the error is erroneously triggered:
@Test
struct S {
var x: Int, y: Int
┬─────────────────
╰─ 🛑 swift-syntax … no way to represent a variable declaration with multiple bindings…
}
@Test
struct Q {
struct R {
var i: Int, j: Int
┬─────────────────
╰─ 🛑 swift-syntax … no way to represent a variable declaration with multiple bindings…
}
}
Steps to Reproduce
Add these two two failing tests to MemberMacroTests (failing on main, I tested 71b7378):
// ...
func testStructVariableDeclWithMultipleBindings() {
struct TestMacro: MemberMacro {
static func expansion(
of node: AttributeSyntax,
providingMembersOf declaration: some DeclGroupSyntax,
in context: some MacroExpansionContext
) throws -> [DeclSyntax] {
return []
}
}
assertMacroExpansion(
"""
@Test
struct S {
var x: Int, y: Int
}
""",
expandedSource: """
struct S {
var x: Int, y: Int
}
""",
macros: ["Test": TestMacro.self],
indentationWidth: indentationWidth
)
}
func testNestedStructVariableDeclWithMultipleBindings() {
struct TestMacro: MemberMacro {
static func expansion(
of node: AttributeSyntax,
providingMembersOf declaration: some DeclGroupSyntax,
in context: some MacroExpansionContext
) throws -> [DeclSyntax] {
return []
}
}
assertMacroExpansion(
"""
@Test
struct Q {
struct R {
var i: Int, j: Int
}
}
""",
expandedSource: """
struct Q {
struct R {
var i: Int, j: Int
}
}
""",
macros: ["Test": TestMacro.self],
indentationWidth: indentationWidth
)
}
// ...