feat: add injector that support contextual injection

Author: AlexisFilipozzi

.github/workflows/go.yml

@@ -0,0 +1,63 @@
+# This workflow will build a golang project
+# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-go
+
+name: Go
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.24'
+
+      - name: Build
+        run: cd inject && go build -v ./...
+
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.24'
+
+      - name: Test
+        run: cd inject && go test -coverprofile=coverage.out ./...
+
+      - name: Upload coverage report
+        uses: codecov/codecov-action@v4
+        with:
+          files: inject/coverage.out
+          fail_ci_if_error: true
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.24'
+
+      - name: Install golangci-lint
+        run: |
+          go install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.64.5
+
+      - name: Run golangci-lint
+        run: cd inject && $(go env GOPATH)/bin/golangci-lint run

.gitignore

@@ -0,0 +1 @@
+.idea

.golangci.yaml

@@ -0,0 +1,152 @@
+linters-settings:
+  gosec:
+    excludes:
+      - G306
+      - G115
+  depguard:
+    # new configuration
+    rules:
+      logger:
+        deny:
+          # logging is allowed only by logutils.Log,
+          # logrus is allowed to use only in logutils package.
+          - pkg: "github.com/sirupsen/logrus"
+            desc: logging is allowed only by logutils.Log
+  dupl:
+    threshold: 100
+  funlen:
+    lines: -1 # the number of lines (code + empty lines) is not a right metric and leads to code without empty line or one-liner.
+    statements: 75
+  goconst:
+    min-len: 2
+    min-occurrences: 3
+  gocritic:
+    enabled-tags:
+      - diagnostic
+      - experimental
+      - opinionated
+      - performance
+      - style
+    disabled-checks:
+      - dupImport # https://github.com/go-critic/go-critic/issues/845
+      - ifElseChain
+      - octalLiteral
+      - whyNoLint
+  gocyclo:
+    min-complexity: 15
+  gofmt:
+    rewrite-rules:
+      - pattern: 'interface{}'
+        replacement: 'any'
+  goimports:
+    local-prefixes: github.com/golangci/golangci-lint
+
+  govet:
+    settings:
+      printf:
+        funcs:
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Infof
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Warnf
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Errorf
+          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Fatalf
+    enable:
+      - nilness
+      - shadow
+  errorlint:
+    asserts: false
+  lll:
+    line-length: 140
+  nolintlint:
+    allow-unused: false # report any unused nolint directives
+    require-explanation: false # don't require an explanation for nolint directives
+    require-specific: false # don't require nolint directives to be specific about which linter is being skipped
+  revive:
+    rules:
+      - name: unexported-return
+        disabled: true
+      - name: unused-parameter
+
+linters:
+  disable-all: true
+  enable:
+    - bodyclose
+    - depguard
+    - dogsled
+    - dupl
+    - errcheck
+    - errorlint
+    - funlen
+    - gocheckcompilerdirectives
+    - gochecknoinits
+    - goconst
+    - gocritic
+    - gocyclo
+    - gofmt
+    - goimports
+    - goprintffuncname
+    - gosec
+    - gosimple
+    - govet
+    - ineffassign
+    - lll
+    - nakedret
+    - noctx
+    - nolintlint
+    - revive
+    - staticcheck
+    - stylecheck
+    - typecheck
+    - unconvert
+    - unparam
+    - unused
+    - whitespace
+
+  # don't enable:
+  # - asciicheck
+  # - scopelint
+  # - gochecknoglobals
+  # - gocognit
+  # - godot
+  # - godox
+  # - goerr113
+  # - interfacer
+  # - maligned
+  # - nestif
+  # - prealloc
+  # - testpackage
+  # - wsl
+
+issues:
+  # Excluding configuration per-path, per-linter, per-text and per-source
+  exclude-rules:
+    - path: pkg/golinters/errcheck.go
+      text: "SA1019: errCfg.Exclude is deprecated: use ExcludeFunctions instead"
+    - path: pkg/commands/run.go
+      text: "SA1019: lsc.Errcheck.Exclude is deprecated: use ExcludeFunctions instead"
+    - path: pkg/commands/run.go
+      text: "SA1019: e.cfg.Run.Deadline is deprecated: Deadline exists for historical compatibility and should not be used."
+
+    - path: pkg/golinters/gofumpt.go
+      text: "SA1019: settings.LangVersion is deprecated: use the global `run.go` instead."
+    - path: pkg/golinters/staticcheck_common.go
+      text: "SA1019: settings.GoVersion is deprecated: use the global `run.go` instead."
+    - path: pkg/lint/lintersdb/manager.go
+      text: "SA1019: (.+).(GoVersion|LangVersion) is deprecated: use the global `run.go` instead."
+    - path: pkg/golinters/unused.go
+      text: "rangeValCopy: each iteration copies 160 bytes \\(consider pointers or indexing\\)"
+    - path: test/(fix|linters)_test.go
+      text: "string `gocritic.go` has 3 occurrences, make it a constant"
+
+    # Due to a change inside go-critic v0.10.0, some reports have been removed,
+    # but as we run analysis with the previous version of golangci-lint this leads to a paradoxical situation.
+    # This exclusion will be removed when the next version of golangci-lint (v1.56.0) will be released.
+    - path: pkg/golinters/nolintlint/nolintlint.go
+      text: "hugeParam: (i|b) is heavy \\(\\d+ bytes\\); consider passing it by pointer"
+  exclude-dirs:
+    - test/testdata_etc # test files
+    - internal/cache # extracted from Go code
+    - internal/renameio # extracted from Go code
+    - internal/robustio # extracted from Go code
+
+run:
+  timeout: 5m

README.md

@@ -0,0 +1,52 @@
+# go-inject
+
+## Description
+
+`go-inject` is a dependency injection library that support contextual scope.
+
+## Example
+
+```go
+package myapp
+
+import (
+	"context"
+
+	"illuin-tech/go-inject/inject"
+)
+
+type key int
+const myScopeKey key = 0
+
+const MyScope = "MyScope"
+
+// define function to declare your own scope in context
+func WithMyScopeEnabled(ctx context.Context) context.Context {
+	return inject.WithContextualScopeEnabled(ctx, myScopeKey)
+}
+
+func ShutdownMyContextScoped(ctx context.Context) {
+	inject.ShutdownContextualScope(ctx, myScopeKey)
+}
+
+// define injection modules
+var Module = inject.Module("myModule",
+	inject.RegisterScope(MyScope, inject.NewContextualScope(myScopeKey)),
+	inject.Provide(func() string {
+		return "Hello world from scope"
+    }, inject.In(MyScope)),
+)
+
+func main() {
+    ctx := context.Background()
+	
+	// enable scope
+	ctx = WithMyScopeEnabled(ctx)
+	defer ShutdownMyContextScoped(ctx)
+	
+	injector := inject.NewInjector(Module)
+	_ = injector.Invoke(ctx, func(hello string) {
+	    println(hello)	
+	})
+}
+```

inject/binding.go

@@ -0,0 +1,36 @@
+package inject
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+)
+
+// binding defines a type mapped to a more concrete type
+type binding struct {
+	typeof        reflect.Type
+	provider      reflect.Value
+	providedType  reflect.Type
+	annotatedWith string
+	scope         string
+	destroyMethod func(value reflect.Value)
+}
+
+func (b *binding) create(ctx context.Context, injector *Injector) (reflect.Value, error) {
+	res, err := injector.callFunctionWithArgumentInstance(ctx, b.provider)
+	if err != nil {
+		return reflect.Value{},
+			fmt.Errorf("failed to call provider function for type %q: %w", b.providedType.String(), err)
+	}
+	if b.provider.Type().NumOut() == 2 {
+		errValue := res[1].Interface()
+		if errValue != nil {
+			err, _ = errValue.(error)
+		}
+	}
+	if err != nil {
+		return res[0], fmt.Errorf("provider for type %q returned error: %w", b.providedType.String(), err)
+	} else {
+		return res[0], nil
+	}
+}

inject/condition.go

@@ -0,0 +1,29 @@
+package inject
+
+import "os"
+
+type Conditional interface {
+	evaluate() bool
+}
+
+type environmentVariableConditional struct {
+	name           string
+	havingValue    string
+	matchIfMissing bool
+}
+
+func (c *environmentVariableConditional) evaluate() bool {
+	val, ok := os.LookupEnv(c.name)
+	if !ok {
+		return c.matchIfMissing
+	}
+	return val == c.havingValue
+}
+
+func OnEnvironmentVariable(name, havingValue string, matchIfMissing bool) Conditional {
+	return &environmentVariableConditional{
+		name:           name,
+		havingValue:    havingValue,
+		matchIfMissing: matchIfMissing,
+	}
+}