fix(dns_record): unify dynamic flags type in list data source

Records returned by the dns_records data source can have differing concrete
underlying types for data.flags (CAA records carry a number while A records
omit the field and decode as a typeless dynamic null). Terraform's list
serialiser requires a uniform element type, so the differing per-record
types crashed the provider with 'inconsistent list element types'.

Normalise the dynamic flags so every element exposes the same underlying
type before constructing the list.

Closes #7004

Signed-off-by: SAY-5 <saiasish.cnp@gmail.com>

Author: SAY-5

internal/services/dns_record/list_data_source.go

@@ -11,6 +11,8 @@ import (
 	"github.com/cloudflare/terraform-provider-cloudflare/internal/customfield"
 	"github.com/hashicorp/terraform-plugin-framework/attr"
 	"github.com/hashicorp/terraform-plugin-framework/datasource"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+	"github.com/hashicorp/terraform-plugin-framework/types/basetypes"
 )
 
 type DNSRecordsDataSource struct {
@@ -92,9 +94,113 @@ func (d *DNSRecordsDataSource) Read(ctx context.Context, req datasource.ReadRequ
 	}
 
 	acc = acc[:min(len(acc), maxItems)]
+
+	// Records returned in the same list may have differing concrete underlying
+	// types for `data.flags` (e.g. CAA records carry a number, A records omit
+	// the field and decode as a typeless dynamic null). Terraform's list
+	// serialiser requires every element of a list to share an identical type,
+	// so the differing per-record types crash the data source with
+	// "inconsistent list element types". Normalise the dynamic flags so every
+	// element exposes the same underlying type before constructing the list.
+	// See https://github.com/cloudflare/terraform-provider-cloudflare/issues/7004
+	normalizeFlagsTypes(ctx, acc)
+
 	result, diags := customfield.NewObjectListFromAttributes[DNSRecordsResultDataSourceModel](ctx, acc)
 	resp.Diagnostics.Append(diags...)
 	data.Result = result
 
 	resp.Diagnostics.Append(resp.State.Set(ctx, &data)...)
 }
+
+// normalizeFlagsTypes ensures every element's `data.flags` exposes the same
+// concrete underlying type. When any sibling carries a known concrete value, an
+// otherwise typeless dynamic null is rewrapped as a typed null of that type so
+// the resulting list has a uniform element type.
+func normalizeFlagsTypes(ctx context.Context, acc []attr.Value) {
+	if len(acc) < 2 {
+		return
+	}
+
+	models := make([]*DNSRecordsResultDataSourceModel, len(acc))
+
+	var concreteType attr.Type
+	for i, el := range acc {
+		obj, ok := el.(customfield.NestedObject[DNSRecordsResultDataSourceModel])
+		if !ok {
+			return
+		}
+		m, diags := obj.Value(ctx)
+		if diags.HasError() || m == nil {
+			return
+		}
+		models[i] = m
+		if concreteType != nil {
+			continue
+		}
+		data, diags := m.Data.Value(ctx)
+		if diags.HasError() || data == nil {
+			continue
+		}
+		dyn, _ := data.Flags.ToDynamicValue(ctx)
+		if dyn.IsNull() || dyn.IsUnknown() {
+			continue
+		}
+		if underlying := dyn.UnderlyingValue(); underlying != nil && !underlying.IsNull() && !underlying.IsUnknown() {
+			concreteType = underlying.Type(ctx)
+		}
+	}
+
+	if concreteType == nil {
+		return
+	}
+
+	typedNull, err := makeTypedDynamicNull(concreteType)
+	if err {
+		return
+	}
+
+	changed := false
+	for _, m := range models {
+		data, diags := m.Data.Value(ctx)
+		if diags.HasError() || data == nil {
+			continue
+		}
+		dyn, _ := data.Flags.ToDynamicValue(ctx)
+		if !dyn.IsNull() {
+			if underlying := dyn.UnderlyingValue(); underlying != nil && !underlying.IsNull() {
+				continue
+			}
+		}
+		data.Flags = typedNull
+		m.Data = customfield.NewObjectMust(ctx, data)
+		changed = true
+	}
+
+	if !changed {
+		return
+	}
+
+	for i, m := range models {
+		obj, diags := customfield.NewObject(ctx, m)
+		if diags.HasError() {
+			return
+		}
+		acc[i] = obj
+	}
+}
+
+// makeTypedDynamicNull wraps a typed null of the given concrete type into a
+// NormalizedDynamicValue so that ToTerraformValue serialises a typed null
+// rather than the unconstrained DynamicPseudoType.
+func makeTypedDynamicNull(t attr.Type) (customfield.NormalizedDynamicValue, bool) {
+	var inner attr.Value
+	switch t.(type) {
+	case basetypes.Float64Type:
+		inner = types.Float64Null()
+	case basetypes.StringType:
+		inner = types.StringNull()
+	default:
+		return customfield.NormalizedDynamicValue{}, true
+	}
+	return customfield.RawNormalizedDynamicValueFrom(inner), false
+}