goenv: ParseGoVersion helper

Author: ydnar

goenv/version.go

@@ -34,7 +34,12 @@ func GetGorootVersion() (major, minor int, err error) {
 	if err != nil {
 		return 0, 0, err
 	}
+	return ParseGoVersion(s)
+}
 
+// ParseGoVersion returns the major and minor version for a given Go version.
+// The input must be in the form of "go$MAJOR.$MINOR$TRAILING", e.g. "go1.23" or "go1.24.0-rc2".
+func ParseGoVersion(s string) (major, minor int, err error) {
 	if s == "" || s[:2] != "go" {
 		return 0, 0, errors.New("could not parse Go version: version does not start with 'go' prefix")
 	}
@@ -54,7 +59,18 @@ func GetGorootVersion() (major, minor int, err error) {
 	if err != nil {
 		return 0, 0, fmt.Errorf("failed to parse version: %s", err)
 	}
-	return
+
+	return major, minor, nil
+}
+
+// WantGoVersion returns true if Go version s is >= major and minor.
+// Returns false if s is not a valid Go version string. See [ParseGoVersion] for more information.
+func WantGoVersion(s string, major, minor int) bool {
+	ma, mi, err := ParseGoVersion(s)
+	if err != nil {
+		return false
+	}
+	return ma >= major && mi >= minor
 }
 
 // GorootVersionString returns the version string as reported by the Go

goenv/version_test.go

@@ -0,0 +1,38 @@
+package goenv
+
+import "testing"
+
+func TestParseGoVersion(t *testing.T) {
+	tests := []struct {
+		v       string
+		major   int
+		minor   int
+		wantErr bool
+	}{
+		{"", 0, 0, true},
+		{"go", 0, 0, true},
+		{"go1", 0, 0, true},
+		{"go.0", 0, 0, true},
+		{"go1.0", 1, 0, false},
+		{"go1.1", 1, 1, false},
+		{"go1.23", 1, 23, false},
+		{"go1.23.5", 1, 23, false},
+		{"go1.23.5-rc6", 1, 23, false},
+		{"go2.0", 2, 0, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.v, func(t *testing.T) {
+			major, minor, err := ParseGoVersion(tt.v)
+			if err == nil && tt.wantErr {
+				t.Errorf("ParseGoVersion(%q): expected err != nil", tt.v)
+			}
+			if err != nil && !tt.wantErr {
+				t.Errorf("ParseGoVersion(%q): expected err == nil", tt.v)
+			}
+			if major != tt.major || minor != tt.minor {
+				t.Errorf("ParseGoVersion(%q): expected %d, %d, nil; got %d, %d, %v",
+					tt.v, tt.major, tt.minor, major, minor, err)
+			}
+		})
+	}
+}