goenv: parse patch version, add func Compare to compare two Go version strings (#4536)

goenv: parse patch version, add func Compare to compare two Go version strings
* Parse tests
* add Compare function to compare two Go version strings
* goenv, builder: parse patch version in Go version string

goenv/version_test.go

@@ -0,0 +1,71 @@
+package goenv
+
+import "testing"
+
+func TestParse(t *testing.T) {
+	tests := []struct {
+		v       string
+		major   int
+		minor   int
+		patch   int
+		wantErr bool
+	}{
+		{"", 0, 0, 0, true},
+		{"go", 0, 0, 0, true},
+		{"go1", 0, 0, 0, true},
+		{"go.0", 0, 0, 0, true},
+		{"go1.0", 1, 0, 0, false},
+		{"go1.1", 1, 1, 0, false},
+		{"go1.23", 1, 23, 0, false},
+		{"go1.23.5", 1, 23, 5, false},
+		{"go1.23.5-rc6", 1, 23, 5, false},
+		{"go2.0", 2, 0, 0, false},
+		{"go2.0.15", 2, 0, 15, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.v, func(t *testing.T) {
+			major, minor, patch, err := Parse(tt.v)
+			if err == nil && tt.wantErr {
+				t.Errorf("Parse(%q): expected err != nil", tt.v)
+			}
+			if err != nil && !tt.wantErr {
+				t.Errorf("Parse(%q): expected err == nil", tt.v)
+			}
+			if major != tt.major || minor != tt.minor || patch != tt.patch {
+				t.Errorf("Parse(%q): expected %d, %d, %d, nil; got %d, %d, %d, %v",
+					tt.v, tt.major, tt.minor, tt.patch, major, minor, patch, err)
+			}
+		})
+	}
+}
+
+func TestCompare(t *testing.T) {
+	tests := []struct {
+		a    string
+		b    string
+		want int
+	}{
+		{"", "", 0},
+		{"go0", "go0", 0},
+		{"go0", "go1", -1},
+		{"go1", "go0", 1},
+		{"go1", "go2", -1},
+		{"go2", "go1", 1},
+		{"go1.1", "go1.2", -1},
+		{"go1.2", "go1.1", 1},
+		{"go1.1.0", "go1.2.0", -1},
+		{"go1.2.0", "go1.1.0", 1},
+		{"go1.2.0", "go2.3.0", -1},
+		{"go1.23.2", "go1.23.10", -1},
+		{"go0.1.22", "go1.23.101", -1},
+	}
+	for _, tt := range tests {
+		t.Run(tt.a+" "+tt.b, func(t *testing.T) {
+			got := Compare(tt.a, tt.b)
+			if got != tt.want {
+				t.Errorf("Compare(%q, %q): expected %d; got %d",
+					tt.a, tt.b, tt.want, got)
+			}
+		})
+	}
+}