refactor: extract stringValueOrNull helper to util.go

Replace the repeated if/else null-on-empty-string pattern at all 4
CORSBehavior read sites with a single stringValueOrNull() call.

Author: ethanndickson

internal/provider/provider.go

@@ -90,7 +90,7 @@ func (p *CoderdProvider) Configure(ctx context.Context, req provider.ConfigureRe
 		if !ok {
 			resp.Diagnostics.AddError("url", "url or $CODER_URL is required")
 			return
-		}
+	}
 		data.URL = types.StringValue(urlEnv)
 	}
 	if data.Token.ValueString() == "" {

internal/provider/template_data_source.go

@@ -335,11 +335,7 @@ func (d *TemplateDataSource) Read(ctx context.Context, req datasource.ReadReques
 	data.TimeTilDormantAutoDeleteMillis = types.Int64Value(template.TimeTilDormantAutoDeleteMillis)
 	data.RequireActiveVersion = types.BoolValue(template.RequireActiveVersion)
 	data.MaxPortShareLevel = types.StringValue(string(template.MaxPortShareLevel))
-	if template.CORSBehavior == "" {
-		data.CORSBehavior = types.StringNull()
-	} else {
-		data.CORSBehavior = types.StringValue(string(template.CORSBehavior))
-	}
+	data.CORSBehavior = stringValueOrNull(string(template.CORSBehavior))
 	data.CreatedByUserID = UUIDValue(template.CreatedByID)
 	data.CreatedAt = types.Int64Value(template.CreatedAt.Unix())
 	data.UpdatedAt = types.Int64Value(template.UpdatedAt.Unix())

internal/provider/template_resource.go

@@ -616,11 +616,7 @@ func (r *TemplateResource) Create(ctx context.Context, req resource.CreateReques
 	}
 
 	// Set cors_behavior from the response (it's set during create via toCreateRequest)
-	if templateResp.CORSBehavior == "" {
-		data.CORSBehavior = types.StringNull()
-	} else {
-		data.CORSBehavior = types.StringValue(string(templateResp.CORSBehavior))
-	}
+	data.CORSBehavior = stringValueOrNull(string(templateResp.CORSBehavior))
 
 	// TODO: Remove this update call (and the attribute) once the provider
 	// requires a Coder version where this flag has been removed.
@@ -680,11 +676,7 @@ func (r *TemplateResource) Read(ctx context.Context, req resource.ReadRequest, r
 		return
 	}
 	data.MaxPortShareLevel = types.StringValue(string(template.MaxPortShareLevel))
-	if template.CORSBehavior == "" {
-		data.CORSBehavior = types.StringNull()
-	} else {
-		data.CORSBehavior = types.StringValue(string(template.CORSBehavior))
-	}
+	data.CORSBehavior = stringValueOrNull(string(template.CORSBehavior))
 	data.UseClassicParameterFlow = types.BoolValue(template.UseClassicParameterFlow)
 
 	if !data.ACL.IsNull() {
@@ -861,11 +853,7 @@ func (r *TemplateResource) Update(ctx context.Context, req resource.UpdateReques
 		return
 	}
 	newState.MaxPortShareLevel = types.StringValue(string(templateResp.MaxPortShareLevel))
-	if templateResp.CORSBehavior == "" {
-		newState.CORSBehavior = types.StringNull()
-	} else {
-		newState.CORSBehavior = types.StringValue(string(templateResp.CORSBehavior))
-	}
+	newState.CORSBehavior = stringValueOrNull(string(templateResp.CORSBehavior))
 
 	resp.Diagnostics.Append(newState.Versions.setPrivateState(ctx, resp.Private)...)
 	if resp.Diagnostics.HasError() {

internal/provider/util.go

@@ -12,6 +12,8 @@ import (
 
 	"github.com/coder/coder/v2/codersdk"
 	"github.com/google/uuid"
+
+	"github.com/hashicorp/terraform-plugin-framework/types"
 )
 
 func PrintOrNull(v any) string {
@@ -123,3 +125,13 @@ func isNotFound(err error) bool {
 	}
 	return false
 }
+
+// stringValueOrNull returns types.StringNull() if s is empty,
+// otherwise types.StringValue(s).
+func stringValueOrNull(s string) types.String {
+	if s == "" {
+		return types.StringNull()
+	}
+	return types.StringValue(s)
+}
+