Avoid parsing known empty inputs

pkg/mapper/configmap/configmap.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -117,21 +118,23 @@ func ParseMap(m map[string]string) (userMappings []config.UserMapping, roleMappi
 	rawUserMappings := make([]config.UserMapping, 0)
 	userMappings = make([]config.UserMapping, 0)
 	if userData, ok := m["mapUsers"]; ok {
-		userJson, err := utilyaml.ToJSON([]byte(userData))
-		if err != nil {
-			errs = append(errs, err)
-		} else {
-			err = json.Unmarshal(userJson, &rawUserMappings)
+		if !isSkippable(userData) {
+			userJson, err := utilyaml.ToJSON([]byte(userData))
 			if err != nil {
 				errs = append(errs, err)
-			}
-
-			for _, userMapping := range rawUserMappings {
-				err = userMapping.Validate()
+			} else {
+				err = json.Unmarshal(userJson, &rawUserMappings)
 				if err != nil {
 					errs = append(errs, err)
-				} else {
-					userMappings = append(userMappings, userMapping)
+				}
+
+				for _, userMapping := range rawUserMappings {
+					err = userMapping.Validate()
+					if err != nil {
+						errs = append(errs, err)
+					} else {
+						userMappings = append(userMappings, userMapping)
+					}
 				}
 			}
 		}
@@ -140,31 +143,35 @@ func ParseMap(m map[string]string) (userMappings []config.UserMapping, roleMappi
 	rawRoleMappings := make([]config.RoleMapping, 0)
 	roleMappings = make([]config.RoleMapping, 0)
 	if roleData, ok := m["mapRoles"]; ok {
-		roleJson, err := utilyaml.ToJSON([]byte(roleData))
-		if err != nil {
-			errs = append(errs, err)
-		} else {
-			err = json.Unmarshal(roleJson, &rawRoleMappings)
+		if !isSkippable(roleData) {
+			roleJson, err := utilyaml.ToJSON([]byte(roleData))
 			if err != nil {
 				errs = append(errs, err)
-			}
-
-			for _, roleMapping := range rawRoleMappings {
-				err = roleMapping.Validate()
+			} else {
+				err = json.Unmarshal(roleJson, &rawRoleMappings)
 				if err != nil {
 					errs = append(errs, err)
-				} else {
-					roleMappings = append(roleMappings, roleMapping)
+				}
+
+				for _, roleMapping := range rawRoleMappings {
+					err = roleMapping.Validate()
+					if err != nil {
+						errs = append(errs, err)
+					} else {
+						roleMappings = append(roleMappings, roleMapping)
+					}
 				}
 			}
 		}
 	}
 
 	awsAccounts = make([]string, 0)
 	if accountsData, ok := m["mapAccounts"]; ok {
-		err := yaml.Unmarshal([]byte(accountsData), &awsAccounts)
-		if err != nil {
-			errs = append(errs, err)
+		if !isSkippable(accountsData) {
+			err := yaml.Unmarshal([]byte(accountsData), &awsAccounts)
+			if err != nil {
+				errs = append(errs, err)
+			}
 		}
 	}
 
@@ -175,6 +182,11 @@ func ParseMap(m map[string]string) (userMappings []config.UserMapping, roleMappi
 	return userMappings, roleMappings, awsAccounts, err
 }
 
+func isSkippable(data string) bool {
+	trimmed := strings.TrimSpace(data)
+	return trimmed == "" || trimmed == "``" || trimmed == "\"\""
+}
+
 func EncodeMap(userMappings []config.UserMapping, roleMappings []config.RoleMapping, awsAccounts []string) (m map[string]string, err error) {
 	m = make(map[string]string)
 

pkg/mapper/configmap/configmap_test.go

@@ -331,3 +331,25 @@ func TestParseMap(t *testing.T) {
 		t.Fatalf("unexpected %v != %v", m1, m2)
 	}
 }
+
+func TestBadParseMap(t *testing.T) {
+	m1 := map[string]string{
+		"mapAccounts": ``,
+		"mapRoles":    `""`,
+		"mapUsers":    "``",
+	}
+
+	u, r, a, err := ParseMap(m1)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	m2, err := EncodeMap(u, r, a)
+	if err != nil {
+		t.Fatal(err)
+	}
+	emptyMap := map[string]string{}
+	if !reflect.DeepEqual(emptyMap, m2) {
+		t.Fatalf("unexpected %v != %v", emptyMap, m2)
+	}
+}