Normalize null value for Images to [] for consistent behavior

Author: ezilber-akamai

linode/producerimagesharegroup/framework_models.go

@@ -2,6 +2,7 @@ package producerimagesharegroup
 
 import (
 	"github.com/hashicorp/terraform-plugin-framework-timetypes/timetypes"
+	"github.com/hashicorp/terraform-plugin-framework/attr"
 	"github.com/hashicorp/terraform-plugin-framework/diag"
 	"github.com/hashicorp/terraform-plugin-framework/types"
 	"github.com/linode/linodego"
@@ -52,10 +53,10 @@ func (data *ResourceModel) FlattenImageShareGroup(
 	)
 
 	// Images must persist in state across CRUD operations but is not returned by the API. It will be maintained
-	// manually as a part of Create, Update, and Read, so we only need to set it here if it is null so that it is
-	// properly typed.
-	if data.Images.IsNull() {
-		data.Images = types.ListNull(imageShareGroupImage.Type())
+	// manually as a part of Create, Update, and Read, so we only need to set it here if it is null or unknown
+	// so that it is properly typed.
+	if data.Images.IsNull() || data.Images.IsUnknown() {
+		data.Images = types.ListValueMust(imageShareGroupImage.Type(), []attr.Value{})
 	}
 }
 

linode/producerimagesharegroup/framework_resource.go

@@ -3,6 +3,7 @@ package producerimagesharegroup
 import (
 	"context"
 	"fmt"
+	"github.com/hashicorp/terraform-plugin-framework/attr"
 
 	"github.com/hashicorp/terraform-plugin-framework/resource"
 	"github.com/hashicorp/terraform-plugin-framework/types"
@@ -164,6 +165,11 @@ func (r *Resource) Read(
 
 	state.Images = listVal
 
+	// Normalize null/unknown -> []
+	if state.Images.IsNull() || state.Images.IsUnknown() {
+		state.Images = types.ListValueMust(imageShareGroupImage.Type(), []attr.Value{})
+	}
+
 	resp.Diagnostics.Append(resp.State.Set(ctx, &state)...)
 }
 
@@ -373,6 +379,11 @@ func (r *Resource) Update(
 	}
 	state.Images = listVal
 
+	// Normalize null/unknown -> []
+	if state.Images.IsNull() || state.Images.IsUnknown() {
+		state.Images = types.ListValueMust(imageShareGroupImage.Type(), []attr.Value{})
+	}
+
 	resp.Diagnostics.Append(resp.State.Set(ctx, &state)...)
 }
 

linode/producerimagesharegroup/framework_schema_resource.go

@@ -4,6 +4,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-framework-timetypes/timetypes"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema/int64planmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/listplanmodifier"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema/stringplanmodifier"
 )
@@ -79,7 +80,11 @@ var frameworkResourceSchema = schema.Schema{
 		"images": schema.ListNestedAttribute{
 			Description:  "The images to be shared using this Image Share Group.",
 			Optional:     true,
+			Computed:     true,
 			NestedObject: imageShareGroupImage,
+			PlanModifiers: []planmodifier.List{
+				listplanmodifier.UseStateForUnknown(),
+			},
 		},
 	},
 }