@testable import PureYAML
import Testing

@Suite("Parsing Error Paths")
struct ParsingErrorPathTests {
    @Test("A node property with no following node is an empty (null) node")
    func test_danglingNodePropertyIsEmptyNode() throws {
        // A property always attaches to a node, and an empty node is allowed, so a dangling anchor
        // or tag denotes a null node carrying that property rather than being an error.
        #expect(try PureYAML.parse("&anchor\n") == .null)
        #expect(try PureYAML.parse("root:\n  key: &a\nother: 1\n") == .mapping(.init([
            .init(key: "root", value: .mapping(.init([.init(key: "key", value: .null)]))),
            .init(key: "other", value: .int(1)),
        ])))
    }

    @Test("An unterminated flow mapping throws at stream end")
    func test_unterminatedFlowMappingThrows() {
        expectParseError("x: {a: b", .malformed(
            reason: "while parsing a flow mapping, did not find expected ',' or '}'",
            line: 1,
            column: 4,
        ))
    }

    @Test("Block scalar content less indented than the explicit indicator throws")
    func test_explicitBlockScalarIndentationUnderIndentThrows() {
        expectParseError("k: |2\n a\n", .malformed(
            reason: "while parsing a block mapping, did not find expected key",
            line: 1,
            column: 1,
        ))
    }

    @Test("Diagnostic validation reports an invalid merge value via the buffered composer")
    func test_diagnosticValidationRejectsInvalidMergeValue() {
        let report = PureYAML.diagnosticValidationReport("a: &x 1\nb:\n  <<: *x\n", file: "merge.yaml")
        #expect(!report.isValid)
        #expect(report.diagnostics.count == 1)
        let diagnostic = report.diagnostics.first
        #expect(diagnostic?.kind == .parse)
        #expect(diagnostic?.code == "invalidMergeValue")
        #expect(diagnostic?.line == 3)
    }
}