@testable import PureYAML
import Testing

@Suite("Flow collections reject empty entries")
struct FlowEmptyEntryTests {
    @Test("A leading or repeated comma is an empty entry and is rejected", arguments: [
        "[ , a, b, c ]\n", // leading comma in a sequence
        "[ a, b, c, , ]\n", // repeated comma in a sequence
        "{ , a: 1 }\n", // leading comma in a mapping
        "{ a: 1, , b: 2 }\n", // repeated comma in a mapping
    ])
    func test_emptyEntryIsRejected(_ yaml: String) throws {
        #expect(throws: PureYAML.Parsing.ParseError.self) {
            try PureYAML.parse(yaml)
        }
    }

    @Test("A single trailing comma and empty collections stay valid")
    func test_trailingCommaAndEmptyCollectionsAccepted() throws {
        #expect(try PureYAML.parse("[ a, b, ]\n") == .sequence(.init([.string("a"), .string("b")])))
        #expect(try PureYAML.parse("[]\n") == .sequence(.init([])))
        #expect(try PureYAML.parse("{ a: 1, }\n") == .mapping(.init([.init(key: "a", value: .int(1))])))
        #expect(try PureYAML.parse("{}\n") == .mapping(.init([])))
    }
}