dix

dix is a lightweight yet powerful dependency injection framework for Go.

Inspired by uber-go/dig, with support for advanced dependency management and namespace isolation.

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✨ Features

Feature	Description
🔄 Cycle Detection	Auto-detect dependency cycles
📦 Multiple Injection	Support func, struct, map, list
🏷️ Namespace	Dependency isolation via map key
🎯 Multi-Output	Struct can provide multiple dependencies
🪆 Nested Support	Support nested struct injection
🔧 Non-Invasive	Zero intrusion to original objects
🛡️ Safe API	TryProvide/TryInject won't panic
🌐 Visualization	HTTP module for dependency graph

📦 Installation

go get github.com/pubgo/dix/v2

🚀 Quick Start

package main

import (
    "fmt"
    "github.com/pubgo/dix/v2"
)

type Config struct {
    DSN string
}

type Database struct {
    Config *Config
}

type UserService struct {
    DB *Database
}

func main() {
    // Create container
    di := dix.New()

    // Register Providers
    dix.Provide(di, func() *Config {
        return &Config{DSN: "postgres://localhost/mydb"}
    })

    dix.Provide(di, func(c *Config) *Database {
        return &Database{Config: c}
    })

    dix.Provide(di, func(db *Database) *UserService {
        return &UserService{DB: db}
    })

    // Inject and use
    dix.Inject(di, func(svc *UserService) {
        fmt.Println("DSN:", svc.DB.Config.DSN)
    })
}

📖 Core API

Provide / TryProvide

Register constructor (Provider) to container:

// Standard version - panics on error
dix.Provide(di, func() *Service { return &Service{} })

// Safe version - returns error
err := dix.TryProvide(di, func() *Service { return &Service{} })
if err != nil {
    log.Printf("Registration failed: %v", err)
}

Inject / TryInject

Inject dependencies from container:

// Function injection
dix.Inject(di, func(svc *Service) {
    svc.DoSomething()
})

// Struct injection
type App struct {
    Service *Service
    Config  *Config
}
app := &App{}
dix.Inject(di, app)

// Safe version
err := dix.TryInject(di, func(svc *Service) {
    // ...
})

Startup Timeout / Slow Provider Warning

Control long-running providers during startup:

• Default provider timeout: 15s
• Disable provider timeout explicitly: dix.WithProviderTimeout(0)
• Default slow provider warning threshold: 2s
• Disable slow provider warning: dix.WithSlowProviderThreshold(0)

di := dix.New(
    // Default `ProviderTimeout` is `15s`
    // Use `dix.WithProviderTimeout(0)` to disable provider timeout
    // Default `SlowProviderThreshold` is `2s`
    // Use `dix.WithSlowProviderThreshold(0)` to disable slow-provider warnings
    dix.WithProviderTimeout(2*time.Second),        // override default (default: 15s, 0 = disabled)
    dix.WithSlowProviderThreshold(300*time.Millisecond), // override default (default: 2s, 0 = disabled)
)

DI Trace Logging (Optional)

Enable step-by-step dependency resolution/injection/provider execution logs:

• Env var: DIX_TRACE_DI
• Default: disabled
• Enable values: 1, true, on, yes, enable, trace, debug

export DIX_TRACE_DI=true

When enabled, dix prints di_trace ... events with structured key-values (provider, input/output types, query kind, parent chain, timeout, etc.).

Note: if DIX_LLM_DIAG_MODE=machine, human-readable text logs are suppressed by design, including di_trace lines.

Diagnostic File Collection (Optional)

You can collect detailed diagnostics into a searchable JSONL file:

• Env var: DIX_DIAG_FILE
• Example: export DIX_DIAG_FILE=.local/dix-diag.jsonl

Behavior rules:

• If DIX_DIAG_FILE is not configured, dix keeps the original behavior (no diagnostic file output).
• If DIX_DIAG_FILE is configured, dix appends diagnostic records to file (trace / error / llm).
• Console verbosity still follows existing controls (DIX_TRACE_DI, DIX_LLM_DIAG_MODE).

Tip:

• Keep console output concise for users.
• Keep detailed records in file for search/LLM/offline troubleshooting.

In-Memory Trace Query (dixtrace, Optional)

Starting from this version, dix also emits unified trace events into an in-memory trace store (dixtrace), which can be queried via HTTP API (/api/trace).

• Default: enabled (in-memory ring buffer)
• Optional file sink env var: DIX_TRACE_FILE
• Example: export DIX_TRACE_FILE=.local/dix-trace.jsonl
• Compatibility fallback: when DIX_TRACE_FILE is not set and DIX_DIAG_FILE is set, trace file sink will reuse DIX_DIAG_FILE in append mode.

/api/trace is optimized for online troubleshooting (filter by operation/status/event/component/provider/output_type). If you need separate trace-only file persistence, set DIX_TRACE_FILE explicitly.

Quick event dictionary:

Event	Meaning
di_trace inject.start	Begin an injection request (component, param_type)
di_trace inject.route	Injection route selected (function or struct)
di_trace provide.start	Begin a provider registration request (component)
di_trace provide.signature	Provider function signature analyzed (input_count, output_count)
di_trace provide.register.output.done	Provider output type registered successfully
di_trace provide.register.failed	Provider registration failed (reason or error)
di_trace resolve.value.search_provider.start	Start searching providers for a dependency type
di_trace resolve.value.found	Dependency value resolved successfully
di_trace resolve.value.not_found	Dependency resolution failed (reason included)
di_trace provider.execute.dispatch	Provider selected for execution (provider, output_type, input_types)
di_trace provider.input.resolve.start	Resolve one provider input type
di_trace provider.input.resolve.found	Provider input resolved
di_trace provider.input.resolve.failed	Provider input resolution failed
di_trace provider.call.start	Start executing provider (timeout)
di_trace provider.call.done	Provider execution completed
di_trace provider.call.failed	Provider execution failed (timed_out, error)
di_trace provider.call.return_error	Provider returned non-nil error
di_trace inject.func.resolve_input.start	Resolve function injection argument
di_trace inject.func.resolve_input.failed	Function argument resolution failed
di_trace inject.struct.field.resolve.start	Resolve one struct field injection
di_trace inject.struct.field.resolve.done	Struct field injected successfully
di_trace inject.struct.field.resolve.failed	Struct field injection failed

🎯 Injection Patterns

Struct Injection

type In struct {
    Config   *Config
    Database *Database
}

type Out struct {
    UserSvc  *UserService
    OrderSvc *OrderService
}

// Multiple inputs and outputs
dix.Provide(di, func(in In) Out {
    return Out{
        UserSvc:  &UserService{DB: in.Database},
        OrderSvc: &OrderService{DB: in.Database},
    }
})

Map Injection (Namespace)

// Provide with namespace
dix.Provide(di, func() map[string]*Database {
    return map[string]*Database{
        "master": &Database{DSN: "master-dsn"},
        "slave":  &Database{DSN: "slave-dsn"},
    }
})

// Inject specific namespace
dix.Inject(di, func(dbs map[string]*Database) {
    master := dbs["master"]
    slave := dbs["slave"]
})

List Injection

// Provide same type multiple times
dix.Provide(di, func() []Handler {
    return []Handler{&AuthHandler{}}
})
dix.Provide(di, func() []Handler {
    return []Handler{&LogHandler{}}
})

// Inject all
dix.Inject(di, func(handlers []Handler) {
    // handlers contains AuthHandler and LogHandler
})

🧩 Modules

dixglobal - Global Container

Provides global singleton container for simple applications:

import "github.com/pubgo/dix/v2/dixglobal"

// Use directly without creating container
dixglobal.Provide(func() *Config { return &Config{} })
dixglobal.Inject(func(c *Config) { /* ... */ })

dixcontext - Context Integration

Bind container to context.Context:

import "github.com/pubgo/dix/v2/dixcontext"

// Store in context
ctx := dixcontext.Create(context.Background(), di)

// Retrieve and use
container := dixcontext.Get(ctx)

dixhttp - Dependency Visualization 🆕

Web interface for visualizing dependency graph, designed for large projects:

import (
    "github.com/pubgo/dix/v2/dixhttp"
    "github.com/pubgo/dix/v2/dixinternal"
)

server := dixhttp.NewServer((*dixinternal.Dix)(di))
server.ListenAndServe(":8080")

Visit http://localhost:8080 to view dependency graph.

Highlights:

• 🔍 Fuzzy Search - Quickly locate types or functions
• 📦 Package Grouping - Collapsible sidebar browsing
• 🔄 Bidirectional Tracking - Show both dependencies and dependents
• 📏 Depth Control - Limit display levels (1-5 or all)
• 🎨 Modern UI - Tailwind CSS + Alpine.js

See dixhttp/README.md for details.

🛠️ Development

# Run tests
task test

# Lint
task lint

# Build
task build

📚 Examples

Example	Description
struct-in	Struct input injection
struct-out	Struct multi-output
func	Function injection
map	Map/namespace injection
map-nil	Map with nil handling
list	List injection
list-nil	List with nil handling
lazy	Lazy injection
cycle	Cycle detection example
handler	Handler pattern
inject_method	Method injection
test-return-error	Error handling
http	HTTP visualization

📖 Documentation

Document	Description
Design Document	Architecture and detailed design
Audit Report	Project audit, evaluation and comparison
dixhttp README	HTTP visualization module documentation

📄 License

MIT