golang

name: golang description: GraphStructManager Go 1.25 + Gremlin guidelines

Overview

You are maintaining GraphStructManager, a type-safe, chainable Gremlin query builder for Go. Prioritize correctness, predictable API behavior, and clear mapping between Go structs and Gremlin traversals.

Inspiration

• The API is inspired by GORM, but adapted for graph databases and Gremlin traversals rather than SQL.

Repository Context

• Go version: 1.25 (module github.com/jbrusegaard/graph-struct-manager)
• Gremlin: Apache TinkerPop gremlin-go v3.7.4
• Core packages: gremlin/driver, gsmtypes, comparator, log
• Public surface: generic query builder (Query[T gsmtypes.VertexType]) and helper APIs

Graph Model Conventions

• Vertex structs must embed gsmtypes.Vertex anonymously; Create/Update validate this.
• Edge structs (when used) embed gsmtypes.Edge and implement gsmtypes.EdgeType.
• Use gremlin:"field_name" tags for properties; gremlin:"field_name,omitempty" skips zero values and nil pointers during create/update.
• Use gremlinSubTraversal:"alias" for subtraversal projections; the alias must match AddSubTraversal usage.
• Use gremlinEdge:"edge_label[,out|in|both]" for related-vertex fields loaded via Preload(goFieldName); nested paths use dots (Preload("Topics.Posts")). These fields are never persisted as properties.
• Label resolution: Label() string wins; empty label defaults to snake_case struct name.

Query Builder Design

• Keep methods chainable and consistent with existing behavior (mutate query, return *Query[T]).
• Use comparator constants for predicates; map them to Gremlin P/TextP consistently.
• Preserve debug string building and GSM_DEBUG behavior when adding query steps.
• Range is ignored when Offset is set; maintain this behavior and warnings.
• Take() returns the first result; ID() performs fast ID lookup using HasLabel.

Struct Mapping and Tags

• structToMap drives create/update; it ignores gremlinSubTraversal tags.
• UnloadGremlinResultIntoStruct maps Gremlin results to tagged fields, including anonymous embedded structs and subtraversal aliases.
• When changing mapping rules, update tests under gremlin/driver/*_test.go.

Logging and Diagnostics

• Logging uses log.InitializeLogger() and GSM_LOG_LEVEL.
• Query debugging uses GSM_DEBUG=true to emit generated traversal strings.

Error Handling

• Return explicit errors; wrap with context (fmt.Errorf("context: %w", err)).
• Avoid panics and hidden behavior changes; align error messages with existing usage.

Testing and Docs

• Prefer table-driven tests and cover exported behavior.
• If you change public API or query semantics, update README.md examples to match.