✨ Support negative integers in marker syntax

This adds support for negative integers in the marker syntax parser.
This is useful for markers like `+kubebuilder:validation:Minimum`.

Signed-off-by: knight42 <[email protected]>

Author: knight42

pkg/crd/markers/validation.go

@@ -106,7 +106,7 @@ func init() {
 type Maximum int
 
 // +controllertools:marker:generateHelp:category="CRD validation"
-// Minimum specifies the minimum numeric value that this field can have.
+// Minimum specifies the minimum numeric value that this field can have. Negative integers are supported.
 type Minimum int
 
 // +controllertools:marker:generateHelp:category="CRD validation"

pkg/markers/parse.go

@@ -340,8 +340,13 @@ func guessType(scanner *sc.Scanner, raw string, allowSlice bool) *Argument {
 		}
 	}
 
+	// then, integers...
 	if !probablyString {
-		if nextTok := subScanner.Scan(); nextTok == sc.Int {
+		nextTok := subScanner.Scan()
+		if nextTok == '-' {
+			nextTok = subScanner.Scan()
+		}
+		if nextTok == sc.Int {
 			return &Argument{Type: IntType}
 		}
 	}
@@ -481,11 +486,21 @@ func (a *Argument) parse(scanner *sc.Scanner, raw string, out reflect.Value, inS
 		for tok := scanner.Scan(); tok != sc.EOF; tok = scanner.Scan() {
 		}
 	case IntType:
+		nextChar := scanner.Peek()
+		isNegative := false
+		if nextChar == '-' {
+			isNegative = true
+			scanner.Scan() // eat the '-'
+		}
 		if !expect(scanner, sc.Int, "integer") {
 			return
 		}
 		// TODO(directxman12): respect the size when parsing
-		val, err := strconv.Atoi(scanner.TokenText())
+		text := scanner.TokenText()
+		if isNegative {
+			text = "-" + text
+		}
+		val, err := strconv.Atoi(text)
 		if err != nil {
 			scanner.Error(scanner, fmt.Sprintf("unable to parse integer: %v", err))
 			return

pkg/markers/parse_test.go

@@ -174,7 +174,7 @@ var _ = Describe("Parsing", func() {
 		It("should support double-quoted strings", argParseTestCase{arg: Argument{Type: StringType}, raw: `"some; string, \nhere"`, output: "some; string, \nhere"}.Run)
 		It("should support raw strings", argParseTestCase{arg: Argument{Type: StringType}, raw: "`some; string, \\nhere`", output: `some; string, \nhere`}.Run)
 		It("should support integers", argParseTestCase{arg: Argument{Type: IntType}, raw: "42", output: 42}.Run)
-		XIt("should support negative integers", argParseTestCase{arg: Argument{Type: IntType}, raw: "-42", output: -42}.Run)
+		It("should support negative integers", argParseTestCase{arg: Argument{Type: IntType}, raw: "-42", output: -42}.Run)
 		It("should support false booleans", argParseTestCase{arg: Argument{Type: BoolType}, raw: "false", output: false}.Run)
 		It("should support true booleans", argParseTestCase{arg: Argument{Type: BoolType}, raw: "true", output: true}.Run)
 
@@ -194,7 +194,7 @@ var _ = Describe("Parsing", func() {
 			It("should support double-quoted strings", argParseTestCase{arg: anyArg, raw: `"some; string, \nhere"`, output: "some; string, \nhere"}.Run)
 			It("should support raw strings", argParseTestCase{arg: anyArg, raw: "`some; string, \\nhere`", output: `some; string, \nhere`}.Run)
 			It("should support integers", argParseTestCase{arg: anyArg, raw: "42", output: 42}.Run)
-			XIt("should support negative integers", argParseTestCase{arg: anyArg, raw: "-42", output: -42}.Run)
+			It("should support negative integers", argParseTestCase{arg: anyArg, raw: "-42", output: -42}.Run)
 			It("should support false booleans", argParseTestCase{arg: anyArg, raw: "false", output: false}.Run)
 			It("should support true booleans", argParseTestCase{arg: anyArg, raw: "true", output: true}.Run)