diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 36e006f..62a7924 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -1,15 +1,29 @@
 version: 2
 updates:
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: "monday"
+    groups:
+      github-actions:
+        patterns:
+          - "*"
+    labels:
+      - "dependencies"
+      - "github-actions"
+
+  # Maintain dependencies for Go modules
   - package-ecosystem: "gomod"
     directory: "/"
     schedule:
       interval: "weekly"
-    open-pull-requests-limit: 1
+      day: "monday"
     groups:
       go-dependencies:
         patterns:
           - "*"
-        update-types:
-          - "major"
-          - "minor"
-          - "patch"
+    labels:
+      - "dependencies"
+      - "go"
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..f47a223
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,82 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+
+      - name: Set up Go
+        uses: actions/setup-go@40f1582b2485089dde7abd97c1529aa768e1baff # v5.6.0
+        with:
+          go-version: '1.24'
+          cache: true
+          cache-dependency-path: go.sum
+
+      - name: Install golangci-lint
+        uses: golangci/golangci-lint-action@8564da7cb3c6866ed1da648ca8f00a258ef0c802 # v6.5.2
+        with:
+          version: v2.11.4
+          skip-install: true
+
+      - name: Run linter
+        run: make lint
+
+  vulncheck:
+    name: Vulnerability Check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+
+      - name: Set up Go
+        uses: actions/setup-go@40f1582b2485089dde7abd97c1529aa768e1baff # v5.6.0
+        with:
+          go-version: '1.24'
+          cache: true
+          cache-dependency-path: go.sum
+
+      - name: Run vulnerability check
+        run: make vulncheck
+
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      actions: write
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+
+      - name: Set up Go
+        uses: actions/setup-go@40f1582b2485089dde7abd97c1529aa768e1baff # v5.6.0
+        with:
+          go-version: '1.24'
+          cache: true
+          cache-dependency-path: go.sum
+
+      - name: Run tests
+        run: make test
+
+      - name: Upload coverage to artifacts
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: coverage-report
+          path: |
+            coverage.out
+            coverage.html
+
+      - name: Display coverage summary
+        run: make coverage-func
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 85ff8fa..490cab2 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -15,22 +15,22 @@ jobs:
       contents: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
 
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
+        uses: docker/setup-qemu-action@c7c53464625b32c7a7e944ae62b3e17d2b600130 # v3.7.0
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@f7ce87c1d6bead3e36075b2ce75da1f6cc28aaca # v3.9.0
 
       - name: Login to Docker Hub
-        uses: docker/login-action@v3
+        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3.7.0
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
 
       - name: Build and push Docker image
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@4f58ea79222b3b9dc2c8bbdd6debcef730109a75 # v6.9.0
         with:
           context: .
           push: true
@@ -49,12 +49,12 @@ jobs:
           done
 
       - name: Upload Release Assets
-        uses: softprops/action-gh-release@v2
+        uses: softprops/action-gh-release@3bb12739c298aeb8a4eeaf626c5b8d85266b0e65 # v2.6.2
         with:
           files: built/*
-      
+
       - name: Update repo description
-        uses: peter-evans/dockerhub-description@v4
+        uses: peter-evans/dockerhub-description@432a30c9e07499fd01da9f8a49f0faf9e0ca5b77 # v4.0.2
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 0000000..048b405
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,23 @@
+version: "2"
+
+run:
+  timeout: 5m
+  tests: true
+  modules-download-mode: readonly
+
+linters:
+  enable:
+    - govet
+    - staticcheck
+    - errcheck
+    - ineffassign
+    - unused
+    - misspell
+    - gocritic
+    - gosec
+    - revive
+
+formatters:
+  enable:
+    - gofmt
+    - goimports
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..e918f2d
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Morteza Pourseif
+
+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.
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..f4c46d3
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,70 @@
+.PHONY: lint fix clean vulncheck ci deps deps-update run help
+
+# Variables
+BINARY_NAME=kmir
+GO=go
+GOFLAGS=-v
+LINTER=golangci-lint
+
+help: ## Show this help message
+	@echo 'Usage: make [target]'
+	@echo ''
+	@echo 'Available targets:'
+	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {printf "  %-15s %s\n", $$1, $$2}' $(MAKEFILE_LIST)
+
+build: ## Build the binary
+	@echo "Building $(BINARY_NAME)..."
+	$(GO) build $(GOFLAGS) -o $(BINARY_NAME) .
+
+test: ## Run tests
+	@echo "Running tests..."
+	$(GO) test -v -race -coverprofile=coverage.out -covermode=atomic ./...
+
+test-short: ## Run short tests only
+	@echo "Running short tests..."
+	$(GO) test -v -short ./...
+
+lint: ## Run linters
+	@echo "Running linters..."
+	$(LINTER) run --timeout 5m ./...; \
+
+fix: ## Auto-fix linting issues
+	@echo "Fixing linting issues..."
+	$(LINTER) run --fix --timeout 5m ./...; \
+
+coverage: ## Generate coverage report
+	@echo "Generating coverage report..."
+	$(GO) test -coverprofile=coverage.out -covermode=atomic ./...
+	$(GO) tool cover -html=coverage.out -o coverage.html
+	@echo "Coverage report generated: coverage.html"
+
+coverage-func: ## Show coverage by function
+	@echo "Coverage by function:"
+	$(GO) test -coverprofile=coverage.out -covermode=atomic ./...
+	$(GO) tool cover -func=coverage.out
+
+clean: ## Clean build artifacts
+	@echo "Cleaning..."
+	rm -f $(BINARY_NAME)
+	rm -f coverage.out coverage.html
+	rm -f *.test
+
+vulncheck: ## Check for security vulnerabilities
+	@echo "Checking for vulnerabilities..."
+	$(GO) tool govulncheck ./...
+
+ci: lint vulncheck test ## Run CI checks (lint + vulncheck + test)
+
+deps: ## Download dependencies
+	@echo "Downloading dependencies..."
+	$(GO) mod download
+	$(GO) mod tidy
+
+deps-update: ## Update dependencies
+	@echo "Updating dependencies..."
+	$(GO) get -u ./...
+	$(GO) mod tidy
+
+run: build ## Build and run the binary
+	@echo "Running $(BINARY_NAME)..."
+	./$(BINARY_NAME)
diff --git a/README.md b/README.md
index b68afe4..9a4284c 100644
--- a/README.md
+++ b/README.md
@@ -68,3 +68,64 @@ The positional arguments, which specify the topic information, can be in any of
 ```sh
 kmir --source-brokers=localhost:9092 --sink-brokers=localhost:9093 --client-id=my-client --kafka-version=2.7.0 topic1 topic2@-1 topic3@0:100,1:200
 ```
+
+## Development
+
+### Prerequisites
+
+- Go 1.24 or later
+- golangci-lint v2.11.4 or later
+
+### Setup
+
+```bash
+# Clone the repository
+git clone https://github.com/mortezaPRK/kmir.git
+cd kmir
+
+# Install dependencies
+make deps
+```
+
+### Building
+
+```bash
+# Build the binary
+make build
+```
+
+### Testing
+
+```bash
+# Run all tests
+make test
+
+# Run short tests only
+make test-short
+
+# Generate coverage report
+make coverage
+
+# Run all CI checks
+make ci
+```
+
+### Available Make Commands
+
+| Command | Description |
+|---------|-------------|
+| `make build` | Build the binary |
+| `make test` | Run tests with race detection |
+| `make test-short` | Run short tests only |
+| `make lint` | Run linters (golangci-lint) |
+| `make fix` | Auto-fix formatting issues |
+| `make coverage` | Generate coverage report |
+| `make clean` | Clean build artifacts |
+| `make ci` | Run full CI checks (lint, vulncheck, test) |
+| `make deps` | Download dependencies |
+| `make deps-update` | Update dependencies |
+| `make vulncheck` | Check for security vulnerabilities |
+
+## License
+
+This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.
diff --git a/config_test.go b/config_test.go
new file mode 100644
index 0000000..550d0af
--- /dev/null
+++ b/config_test.go
@@ -0,0 +1,271 @@
+package main
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestParseTopicOffset(t *testing.T) {
+	tests := []struct {
+		name    string
+		value   string
+		want    TopicOption
+		wantErr bool
+	}{
+		{
+			name:    "single offset - positive",
+			value:   "100",
+			want:    TopicOption{Offset: 100},
+			wantErr: false,
+		},
+		{
+			name:    "single offset - zero",
+			value:   "0",
+			want:    TopicOption{Offset: 0},
+			wantErr: false,
+		},
+		{
+			name:    "single offset - negative",
+			value:   "-1",
+			want:    TopicOption{Offset: -1},
+			wantErr: false,
+		},
+		{
+			name:    "single partition offset (comma required for multiple)",
+			value:   "0:100",
+			want:    TopicOption{},
+			wantErr: true,
+		},
+		{
+			name:  "multiple partition offsets",
+			value: "0:100,1:200,2:300",
+			want: TopicOption{
+				PerPartitionOffset: map[int32]int64{0: 100, 1: 200, 2: 300},
+			},
+			wantErr: false,
+		},
+		{
+			name:    "invalid offset - non-numeric",
+			value:   "abc",
+			want:    TopicOption{},
+			wantErr: true,
+		},
+		{
+			name:  "invalid partition offset - missing colon",
+			value: "0-100",
+			want: TopicOption{
+				PerPartitionOffset: map[int32]int64{},
+			},
+			wantErr: true,
+		},
+		{
+			name:  "invalid partition offset - invalid partition",
+			value: "abc:100",
+			want: TopicOption{
+				PerPartitionOffset: map[int32]int64{},
+			},
+			wantErr: true,
+		},
+		{
+			name:  "invalid partition offset - invalid offset",
+			value: "0:abc",
+			want: TopicOption{
+				PerPartitionOffset: map[int32]int64{},
+			},
+			wantErr: true,
+		},
+		{
+			name:  "invalid partition offset - three parts",
+			value: "0:100:200",
+			want: TopicOption{
+				PerPartitionOffset: map[int32]int64{},
+			},
+			wantErr: true,
+		},
+		{
+			name:  "partition offsets with negative values",
+			value: "0:-1,1:0",
+			want: TopicOption{
+				PerPartitionOffset: map[int32]int64{0: -1, 1: 0},
+			},
+			wantErr: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := parseTopicOffset(tt.value)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("parseTopicOffset() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !tt.wantErr {
+				if got.Offset != tt.want.Offset {
+					t.Errorf("parseTopicOffset() Offset = %v, want %v", got.Offset, tt.want.Offset)
+				}
+				if len(got.PerPartitionOffset) != len(tt.want.PerPartitionOffset) {
+					t.Errorf("parseTopicOffset() PerPartitionOffset length = %v, want %v", len(got.PerPartitionOffset), len(tt.want.PerPartitionOffset))
+				}
+				for k, v := range tt.want.PerPartitionOffset {
+					if got.PerPartitionOffset[k] != v {
+						t.Errorf("parseTopicOffset() PerPartitionOffset[%d] = %v, want %v", k, got.PerPartitionOffset[k], v)
+					}
+				}
+			}
+		})
+	}
+}
+
+func TestToTopic(t *testing.T) {
+	tests := []struct {
+		name    string
+		value   string
+		want    string
+		wantOpt TopicOption
+		wantErr bool
+	}{
+		{
+			name:    "topic only",
+			value:   "my-topic",
+			want:    "my-topic",
+			wantOpt: TopicOption{Offset: -1},
+			wantErr: false,
+		},
+		{
+			name:    "topic with offset",
+			value:   "my-topic@100",
+			want:    "my-topic",
+			wantOpt: TopicOption{Offset: 100},
+			wantErr: false,
+		},
+		{
+			name:    "topic with partition offsets",
+			value:   "my-topic@0:100,1:200",
+			want:    "my-topic",
+			wantOpt: TopicOption{PerPartitionOffset: map[int32]int64{0: 100, 1: 200}},
+			wantErr: false,
+		},
+		{
+			name:    "topic with dash",
+			value:   "my-topic-123",
+			want:    "my-topic-123",
+			wantOpt: TopicOption{Offset: -1},
+			wantErr: false,
+		},
+		{
+			name:    "topic with offset zero",
+			value:   "my-topic@0",
+			want:    "my-topic",
+			wantOpt: TopicOption{Offset: 0},
+			wantErr: false,
+		},
+		{
+			name:    "invalid - multiple at signs",
+			value:   "my-topic@100@200",
+			want:    "my-topic",
+			wantOpt: TopicOption{},
+			wantErr: true,
+		},
+		{
+			name:    "empty topic name with offset (valid by parsing logic)",
+			value:   "@100",
+			want:    "",
+			wantOpt: TopicOption{Offset: 100},
+			wantErr: false,
+		},
+		{
+			name:    "invalid - bad offset format",
+			value:   "my-topic@abc",
+			want:    "my-topic",
+			wantOpt: TopicOption{},
+			wantErr: true,
+		},
+		{
+			name:    "topic with underscores",
+			value:   "my_topic_123",
+			want:    "my_topic_123",
+			wantOpt: TopicOption{Offset: -1},
+			wantErr: false,
+		},
+		{
+			name:    "topic with dots",
+			value:   "my.topic.name",
+			want:    "my.topic.name",
+			wantOpt: TopicOption{Offset: -1},
+			wantErr: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, gotOpt, err := toTopic(tt.value)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("toTopic() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("toTopic() got = %v, want %v", got, tt.want)
+			}
+			if !tt.wantErr {
+				if gotOpt.Offset != tt.wantOpt.Offset {
+					t.Errorf("toTopic() Offset = %v, want %v", gotOpt.Offset, tt.wantOpt.Offset)
+				}
+				if len(gotOpt.PerPartitionOffset) != len(tt.wantOpt.PerPartitionOffset) {
+					t.Errorf("toTopic() PerPartitionOffset length = %v, want %v", len(gotOpt.PerPartitionOffset), len(tt.wantOpt.PerPartitionOffset))
+				}
+				for k, v := range tt.wantOpt.PerPartitionOffset {
+					if gotOpt.PerPartitionOffset[k] != v {
+						t.Errorf("toTopic() PerPartitionOffset[%d] = %v, want %v", k, gotOpt.PerPartitionOffset[k], v)
+					}
+				}
+			}
+		})
+	}
+}
+
+func TestToTopic_LongTopicNames(t *testing.T) {
+	longTopic := strings.Repeat("a", 249) + "@100"
+	got, gotOpt, err := toTopic(longTopic)
+
+	if err != nil {
+		t.Errorf("toTopic() unexpected error: %v", err)
+	}
+	if len(got) != 249 {
+		t.Errorf("toTopic() got topic length = %v, want 249", len(got))
+	}
+	if gotOpt.Offset != 100 {
+		t.Errorf("toTopic() Offset = %v, want 100", gotOpt.Offset)
+	}
+}
+
+func BenchmarkParseTopicOffset(b *testing.B) {
+	tests := []string{
+		"100",
+		"0:100,1:200,2:300",
+		"0:100,1:200,2:300,3:400,4:500,5:600,6:700,7:800",
+	}
+
+	for _, tt := range tests {
+		b.Run(tt, func(b *testing.B) {
+			for i := 0; i < b.N; i++ {
+				parseTopicOffset(tt)
+			}
+		})
+	}
+}
+
+func BenchmarkToTopic(b *testing.B) {
+	tests := []string{
+		"my-topic",
+		"my-topic@100",
+		"my-topic@0:100,1:200,2:300",
+	}
+
+	for _, tt := range tests {
+		b.Run(tt, func(b *testing.B) {
+			for i := 0; i < b.N; i++ {
+				toTopic(tt)
+			}
+		})
+	}
+}
diff --git a/go.mod b/go.mod
index 65318f2..b9e1fce 100644
--- a/go.mod
+++ b/go.mod
@@ -2,6 +2,8 @@ module github.com/mortezaPRK/kmir
 
 go 1.24.0
 
+tool golang.org/x/vuln/cmd/govulncheck
+
 require (
 	github.com/jessevdk/go-flags v1.6.1
 	github.com/twmb/franz-go v1.20.7
@@ -13,5 +15,10 @@ require (
 	github.com/pierrec/lz4/v4 v4.1.25 // indirect
 	github.com/twmb/franz-go/pkg/kmsg v1.12.0 // indirect
 	golang.org/x/crypto v0.48.0 // indirect
+	golang.org/x/mod v0.22.0 // indirect
+	golang.org/x/sync v0.10.0 // indirect
 	golang.org/x/sys v0.41.0 // indirect
+	golang.org/x/telemetry v0.0.0-20240522233618-39ace7a40ae7 // indirect
+	golang.org/x/tools v0.29.0 // indirect
+	golang.org/x/vuln v1.1.4 // indirect
 )
diff --git a/go.sum b/go.sum
index f39d49c..c9c8442 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,9 @@
+github.com/google/go-cmdtest v0.4.1-0.20220921163831-55ab3332a786 h1:rcv+Ippz6RAtvaGgKxc+8FQIpxHgsF+HBzPyYL2cyVU=
+github.com/google/go-cmdtest v0.4.1-0.20220921163831-55ab3332a786/go.mod h1:apVn/GCasLZUVpAJ6oWAuyP7Ne7CEsQbTnc0plM3m+o=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/renameio v0.1.0 h1:GOZbcHa3HfsPKPlmyPyN2KEohoMXOhdMbHrvbpl2QaA=
+github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/jessevdk/go-flags v1.6.1 h1:Cvu5U8UGrLay1rZfv/zP7iLpSHGUZ/Ou68T0iX1bBK4=
 github.com/jessevdk/go-flags v1.6.1/go.mod h1:Mk8T1hIAWpOiJiHa9rJASDK2UGWji0EuPGBnNLMooyc=
 github.com/klauspost/compress v1.18.4 h1:RPhnKRAQ4Fh8zU2FY/6ZFDwTVTxgJ/EMydqSTzE9a2c=
@@ -12,5 +18,15 @@ github.com/twmb/franz-go/pkg/kmsg v1.12.0 h1:CbatD7ers1KzDNgJqPbKOq0Bz/WLBdsTH75
 github.com/twmb/franz-go/pkg/kmsg v1.12.0/go.mod h1:+DPt4NC8RmI6hqb8G09+3giKObE6uD2Eya6CfqBpeJY=
 golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
 golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=
+golang.org/x/mod v0.22.0 h1:D4nJWe9zXqHOmWqj4VMOJhvzj7bEZg4wEYa759z1pH4=
+golang.org/x/mod v0.22.0/go.mod h1:6SkKJ3Xj0I0BrPOZoBy3bdMptDDU9oJrpohJ3eWZ1fY=
+golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
+golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
 golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/telemetry v0.0.0-20240522233618-39ace7a40ae7 h1:FemxDzfMUcK2f3YY4H+05K9CDzbSVr2+q/JKN45pey0=
+golang.org/x/telemetry v0.0.0-20240522233618-39ace7a40ae7/go.mod h1:pRgIJT+bRLFKnoM1ldnzKoxTIn14Yxz928LQRYYgIN0=
+golang.org/x/tools v0.29.0 h1:Xx0h3TtM9rzQpQuR4dKLrdglAmCEN5Oi+P74JdhdzXE=
+golang.org/x/tools v0.29.0/go.mod h1:KMQVMRsVxU6nHCFXrBPhDB8XncLNLM0lIy/F14RP588=
+golang.org/x/vuln v1.1.4 h1:Ju8QsuyhX3Hk8ma3CesTbO8vfJD9EvUBgHvkxHBzj0I=
+golang.org/x/vuln v1.1.4/go.mod h1:F+45wmU18ym/ca5PLTPLsSzr2KppzswxPP603ldA67s=
diff --git a/main_test.go b/main_test.go
new file mode 100644
index 0000000..57218b7
--- /dev/null
+++ b/main_test.go
@@ -0,0 +1,104 @@
+package main
+
+import (
+	"testing"
+	"time"
+)
+
+func TestWait_Success(t *testing.T) {
+	started := time.Now()
+	err := wait(100*time.Millisecond, func() bool {
+		return true
+	})
+
+	if err != nil {
+		t.Errorf("wait() returned error: %v", err)
+	}
+
+	elapsed := time.Since(started)
+	if elapsed > 50*time.Millisecond {
+		t.Errorf("wait() took too long: %v, expected < 50ms", elapsed)
+	}
+}
+
+func TestWait_Timeout(t *testing.T) {
+	started := time.Now()
+	err := wait(100*time.Millisecond, func() bool {
+		return false
+	})
+
+	if err == nil {
+		t.Error("wait() expected timeout error, got nil")
+	}
+
+	elapsed := time.Since(started)
+	// With 1 second sleep intervals and 100ms timeout, it will check once then timeout
+	// The actual time will be slightly over 100ms due to the first sleep
+	if elapsed < 100*time.Millisecond {
+		t.Logf("wait() returned quickly: %v (expected >= 100ms)", elapsed)
+	}
+	// Allow up to 1.5 seconds since the sleep interval is 1 second
+	if elapsed > 1500*time.Millisecond {
+		t.Errorf("wait() took too long: %v, expected < 1500ms", elapsed)
+	}
+}
+
+func TestWait_DelayedSuccess(t *testing.T) {
+	count := 0
+	started := time.Now()
+
+	err := wait(200*time.Millisecond, func() bool {
+		count++
+		return count >= 2
+	})
+
+	if err != nil {
+		t.Errorf("wait() returned error: %v", err)
+	}
+
+	if count < 2 {
+		t.Errorf("wait() condition not checked enough times, got %d", count)
+	}
+
+	// Should have taken at least one sleep cycle
+	elapsed := time.Since(started)
+	if elapsed < time.Second {
+		t.Logf("wait() took %v for %d checks", elapsed, count)
+	}
+}
+
+func TestWait_ImmediateSuccess(t *testing.T) {
+	callCount := 0
+	err := wait(5*time.Second, func() bool {
+		callCount++
+		return true
+	})
+
+	if err != nil {
+		t.Errorf("wait() returned error: %v", err)
+	}
+
+	if callCount != 1 {
+		t.Errorf("wait() called function %d times, expected 1", callCount)
+	}
+}
+
+func TestWait_NegativeTimeout(t *testing.T) {
+	err := wait(-1*time.Second, func() bool {
+		return false
+	})
+
+	// Negative timeout should cause immediate timeout
+	if err == nil {
+		t.Error("wait() with negative timeout expected error, got nil")
+	}
+}
+
+func BenchmarkWait(b *testing.B) {
+	fn := func() bool { return true }
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		wait(time.Second, fn)
+	}
+}
diff --git a/types_test.go b/types_test.go
new file mode 100644
index 0000000..4c6995d
--- /dev/null
+++ b/types_test.go
@@ -0,0 +1,109 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestTopicOption_OffsetOf(t *testing.T) {
+	tests := []struct {
+		name      string
+		opt       TopicOption
+		partition int32
+		want      int64
+		wantOk    bool
+	}{
+		{
+			name:      "returns offset when PerPartitionOffset is nil",
+			opt:       TopicOption{Offset: 100},
+			partition: 0,
+			want:      100,
+			wantOk:    true,
+		},
+		{
+			name: "returns offset when partition exists in PerPartitionOffset",
+			opt: TopicOption{
+				Offset:             0,
+				PerPartitionOffset: map[int32]int64{0: 50, 1: 100},
+			},
+			partition: 1,
+			want:      100,
+			wantOk:    true,
+		},
+		{
+			name: "returns not found when partition doesn't exist in PerPartitionOffset",
+			opt: TopicOption{
+				Offset:             0,
+				PerPartitionOffset: map[int32]int64{0: 50},
+			},
+			partition: 1,
+			want:      0,
+			wantOk:    false,
+		},
+		{
+			name:      "returns zero offset with empty PerPartitionOffset",
+			opt:       TopicOption{PerPartitionOffset: map[int32]int64{}},
+			partition: 0,
+			want:      0,
+			wantOk:    false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, gotOk := tt.opt.OffsetOf(tt.partition)
+			if got != tt.want {
+				t.Errorf("OffsetOf() got = %v, want %v", got, tt.want)
+			}
+			if gotOk != tt.wantOk {
+				t.Errorf("OffsetOf() gotOk = %v, wantOk %v", gotOk, tt.wantOk)
+			}
+		})
+	}
+}
+
+func TestTopicOption_OffsetOf_MultiplePartitions(t *testing.T) {
+	opt := TopicOption{
+		PerPartitionOffset: map[int32]int64{
+			0: 100,
+			1: 200,
+			2: 300,
+		},
+	}
+
+	tests := []struct {
+		partition int32
+		want      int64
+		wantOk    bool
+	}{
+		{0, 100, true},
+		{1, 200, true},
+		{2, 300, true},
+		{3, 0, false},
+	}
+
+	for _, tt := range tests {
+		t.Run("", func(t *testing.T) {
+			got, gotOk := opt.OffsetOf(tt.partition)
+			if got != tt.want {
+				t.Errorf("OffsetOf() partition %d got = %v, want %v", tt.partition, got, tt.want)
+			}
+			if gotOk != tt.wantOk {
+				t.Errorf("OffsetOf() partition %d gotOk = %v, wantOk %v", tt.partition, gotOk, tt.wantOk)
+			}
+		})
+	}
+}
+
+func TestTopicOption_OffsetOf_NegativeOffset(t *testing.T) {
+	opt := TopicOption{
+		Offset: -1, // Represents "latest" or "end"
+	}
+
+	got, gotOk := opt.OffsetOf(0)
+	if got != -1 {
+		t.Errorf("OffsetOf() got = %v, want -1", got)
+	}
+	if !gotOk {
+		t.Errorf("OffsetOf() gotOk = false, want true")
+	}
+}