Initial commit: Thread-safe ordered map for Go

- Insertion order preservation with O(1) lookups
- Thread-safe with RWMutex
- Zero-value usable
- Generic support (Go 1.18+)
- Snapshot-based iteration (deadlock-free)
- 100% test coverage with race detection

Author: ndbroadbent

.github/workflows/test.yml

@@ -0,0 +1,68 @@
+name: Test
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: ['1.22', '1.23', '1.24']
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: ${{ matrix.go-version }}
+
+    - name: Download dependencies
+      run: go mod download
+
+    - name: Run tests
+      run: go test -v -race -coverprofile=coverage.txt -covermode=atomic
+
+    - name: Check coverage
+      run: |
+        coverage=$(go tool cover -func=coverage.txt | grep total | awk '{print $3}' | sed 's/%//')
+        echo "Coverage: $coverage%"
+        if (( $(echo "$coverage < 100" | bc -l) )); then
+          echo "Error: Coverage is below 100%"
+          exit 1
+        fi
+
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v4
+      with:
+        files: ./coverage.txt
+        fail_ci_if_error: false
+        token: ${{ secrets.CODECOV_TOKEN }}
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      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/[email protected]
+
+    - name: Verify golangci-lint config
+      run: golangci-lint config verify
+
+    - name: Run golangci-lint
+      run: golangci-lint run --timeout=5m ./...

.gitignore

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+# Binaries
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary
+*.test
+
+# Coverage
+coverage.txt
+coverage.out
+coverage.html
+
+# Dependency directories
+vendor/
+
+# Go workspace
+go.work
+go.work.sum
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db

.golangci.yml

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+# golangci-lint configuration
+# v2.5.0-ready: explicit, stable linter set + v2 formatters
+
+version: "2"
+
+run:
+  timeout: 5m
+  tests: true
+
+# Formatters live here in v2 (not in linters.enable)
+formatters:
+  enable:
+    - gofumpt
+    - gofmt
+    - goimports
+  settings:
+    goimports:
+      local-prefixes:
+        - github.com/ndbroadbent/db_cutover_orchestrator
+    gofumpt:
+      extra-rules: true
+      module-path: github.com/ndbroadbent/db_cutover_orchestrator
+
+linters:
+  default: none
+  enable:
+    # Core analysis (default enabled linters)
+    - govet
+    - staticcheck
+    - errcheck
+    - ineffassign
+    - unused
+
+    # Error handling
+    - nilerr
+    - forcetypeassert
+
+    # Code quality
+    - revive
+    - gocritic
+
+    # Bugs/correctness
+    - bodyclose
+    - contextcheck
+    - copyloopvar # v2 replacement for exportloopref
+    - noctx
+
+    # Performance
+    - prealloc
+
+    # Complexity
+    - funlen
+    - gocognit
+    - gocyclo
+
+    # Security / policy
+    - gosec
+    - forbidigo
+    - depguard
+
+    # Style
+    - lll
+
+  exclusions:
+    rules:
+      # Allow longer test functions and some duplication in tests
+      - path: _test\.go
+        linters:
+          - funlen
+          - dupl
+          - forbidigo
+          - gosec
+          - gocognit
+      # Allow fmt.Print* in CLI commands (legitimate stdout output)
+      - path: internal/cmd/
+        linters:
+          - forbidigo
+      # Allow file operations in config and state packages
+      - path: internal/(config|state)/
+        text: "G304.*file inclusion"
+        linters:
+          - gosec
+
+  settings:
+    lll:
+      line-length: 120
+      tab-width: 1
+
+    funlen:
+      lines: 100
+      statements: 50
+
+    gocognit:
+      min-complexity: 15
+
+    gocyclo:
+      min-complexity: 15
+
+    forbidigo:
+      forbid:
+        - pattern: '^fmt\.Print.*'
+          msg: "use proper logging instead of fmt.Print"
+        - pattern: "^panic"
+          msg: "use error returns instead of panic"
+        - pattern: '^time\.Sleep'
+          msg: "use context with timeout instead of time.Sleep"
+      exclude-godoc-examples: true
+      analyze-types: true
+
+    depguard:
+      rules:
+        main:
+          list-mode: lax
+          files: [$all]
+          allow:
+            - $gostd
+            - github.com/ndbroadbent/db_cutover_orchestrator
+          deny:
+            - pkg: io/ioutil$
+              desc: "use io or os instead"
+
+issues:
+  max-issues-per-linter: 0
+  max-same-issues: 0

LICENSE

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+MIT License
+
+Copyright (c) 2025 DocSpring, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.