feat: add fromJSON support (#352)

Author: theowenyoung

pkg/runner/expression.go

@@ -132,6 +132,7 @@ func (rc *RunContext) newVM() *otto.Otto {
 		vmFormat,
 		vmJoin,
 		vmToJSON,
+		vmFromJSON,
 		vmAlways,
 		rc.vmCancelled(),
 		rc.vmSuccess(),
@@ -219,6 +220,20 @@ func vmToJSON(vm *otto.Otto) {
 	_ = vm.Set("toJson", toJSON)
 }
 
+func vmFromJSON(vm *otto.Otto) {
+	fromJSON := func(str string) map[string]interface{} {
+		var dat map[string]interface{}
+		err := json.Unmarshal([]byte(str), &dat)
+		if err != nil {
+			logrus.Errorf("Unable to unmarshal: %v", err)
+			return dat
+		}
+		return dat
+	}
+	_ = vm.Set("fromJSON", fromJSON)
+	_ = vm.Set("fromJson", fromJSON)
+}
+
 func (rc *RunContext) vmHashFiles() func(*otto.Otto) {
 	return func(vm *otto.Otto) {
 		_ = vm.Set("hashFiles", func(path string) string {

pkg/runner/expression_test.go

@@ -80,6 +80,8 @@ func TestEvaluate(t *testing.T) {
 		{"join('hello','mona')", "hello mona", ""},
 		{"toJSON({'foo':'bar'})", "{\n  \"foo\": \"bar\"\n}", ""},
 		{"toJson({'foo':'bar'})", "{\n  \"foo\": \"bar\"\n}", ""},
+		{"(fromJSON('{\"foo\":\"bar\"}')).foo", "bar", ""},
+		{"(fromJson('{\"foo\":\"bar\"}')).foo", "bar", ""},
 		{"hashFiles('**/package-lock.json')", "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855", ""},
 		{"success()", "true", ""},
 		{"failure()", "false", ""},