feat: use custom type for nested object struct fields

[hanneshayashi]

Problem

When a StringAttribute has a CustomType (e.g., jsontypes.NormalizedType{}), the generated schema correctly includes the custom type, but the struct field inside nested object value types (like NodeValue.Props) was always generated as basetypes.StringValue instead of the custom value type (e.g., jsontypes.Normalized).

This happened because AttrValue() and AttrType() only checked for AssociatedExternalType and ignored CustomType. Meanwhile, ModelField() (used for top-level model structs) correctly used CustomType.ValueType() — causing an inconsistency.

Fix

• Add TypeString() method to CustomTypePrimitive to expose the type string
• Update AttrValue() and AttrType() in datasource, resource, and provider packages to check CustomType.ValueType() / CustomType.TypeString() before falling back to basetypes.StringValue / basetypes.StringType{}

Before / After

// Before (incorrect):
type NodeValue struct {
    Props  basetypes.StringValue `tfsdk:"props"`
}

// After (correct):
type NodeValue struct {
    Props  jsontypes.Normalized `tfsdk:"props"`
}

Tests

• Added TestCustomTypePrimitive_TypeString and TestCustomTypePrimitive_ValueType (7 cases)
• Added TestGeneratorStringAttribute_AttrType and TestGeneratorStringAttribute_AttrValue (6 cases)
• All existing tests pass

[Copilot]

Pull request overview

This PR addresses a codegen inconsistency where StringAttribute custom types were applied in generated schema (and top-level model fields) but not respected when generating nested object struct field value types, causing nested fields to default to basetypes.StringValue.

Changes:

• Added TypeString() to convert.CustomTypePrimitive to expose the configured custom attr type string.
• Updated AttrType() / AttrValue() for string attributes in datasource, provider, and resource generators to return CustomType types/values when configured.
• Added unit tests covering CustomTypePrimitive and datasource GeneratorStringAttribute attr type/value behavior.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
internal/resource/string_attribute.go	Uses custom type type/value strings for generated attr type/value of string attributes.
internal/provider/string_attribute.go	Uses custom type type/value strings for generated attr type/value of string attributes.
internal/datasource/string_attribute.go	Uses custom type type/value strings for generated attr type/value of string attributes.
internal/datasource/string_attribute_test.go	Adds tests for AttrType()/AttrValue() on datasource string attributes.
internal/convert/custom_type_primitive.go	Adds TypeString() accessor for spec custom type string.
internal/convert/custom_type_primitive_test.go	Adds tests for TypeString() and ValueType() precedence behavior.

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[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.