Check if value is provided

cmd/config/internal/commands/cmdset.go

@@ -71,6 +71,11 @@ func (r *SetRunner) preRunE(c *cobra.Command, args []string) error {
 		return errors.Errorf("value should set either from flag or arg")
 	}
 
+	// make sure that the value is provided either through values flag or as an arg
+	if !valueFlagSet && len(args) < 3 {
+		return errors.Errorf("value must be provided either from flag or arg")
+	}
+
 	r.Name = args[1]
 	if valueFlagSet {
 		r.Value = r.Values[0]

cmd/config/internal/commands/cmdset_test.go

@@ -603,6 +603,54 @@ spec:
 			errMsg: `value should set either from flag or arg`,
 		},
 
+		{
+			name: "value must be provided from either flag or arg",
+			args: []string{"replicas", "--description", "hi there"},
+			inputOpenAPI: `
+apiVersion: v1alpha1
+kind: Example
+openAPI:
+  definitions:
+    io.k8s.cli.setters.replicas:
+      description: hello world
+      x-k8s-cli:
+        setter:
+          name: replicas
+          value: "3"
+          setBy: me
+ `,
+			input: `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: nginx-deployment
+spec:
+  replicas: 3 # {"$ref":"#/definitions/io.k8s.cli.setters.replicas"}
+ `,
+			expectedOpenAPI: `
+apiVersion: v1alpha1
+kind: Example
+openAPI:
+  definitions:
+    io.k8s.cli.setters.replicas:
+      description: hello world
+      x-k8s-cli:
+        setter:
+          name: replicas
+          value: "3"
+          setBy: me
+ `,
+			expectedResources: `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: nginx-deployment
+spec:
+  replicas: 3 # {"$ref":"#/definitions/io.k8s.cli.setters.replicas"}
+ `,
+			errMsg: `value must be provided either from flag or arg`,
+		},
+
 		{
 			name: "openAPI list values set by flag success",
 			args: []string{"list", "--values", "10", "--values", "11"},