Add benchmarks

.github/workflows/go.yml

@@ -1,9 +1,12 @@
 name: CI
 
-on: [push, pull_request]
+on:
+  - push
+  - pull_request
 
 jobs:
   build:
+    name: Build and test
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
@@ -21,3 +24,42 @@ jobs:
 
     - name: Upload coverage to Codecov
       run: bash <(curl -s https://codecov.io/bash)
+
+  benchmark:
+    name: Benchmark
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Go
+        uses: actions/setup-go@v3
+        with:
+          go-version: 1.18
+
+      # Run benchmark with `go test -bench` and stores the output to a file
+      - name: Run benchmark
+        run: go test -bench . | tee output.txt
+
+      # Download previous benchmark result from cache (if exists)
+      - name: Download previous benchmark data
+        uses: actions/cache@v3
+        with:
+          path: ./cache
+          key: ${{ runner.os }}-benchmark
+
+      # Run `github-action-benchmark` action
+      - name: Store benchmark result
+        uses: benchmark-action/github-action-benchmark@v1
+        with:
+          # What benchmark tool the output.txt came from
+          tool: 'go'
+          # Where the output from the benchmark tool is stored
+          output-file-path: output.txt
+          # Where the previous data file is stored
+          external-data-json-path: ./cache/benchmark-data.json
+          # Workflow will fail when an alert happens
+          fail-on-alert: true
+          # GitHub API token to make a commit comment
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          # Enable alert commit comment
+          comment-on-alert: true

sliceutils.go

@@ -114,7 +114,7 @@ func Filter[T any](slice []T, filterFn func(T) bool) []T {
 	if slice == nil {
 		return nil
 	}
-	outSlice := make([]T, 0)
+	outSlice := make([]T, 0, len(slice))
 	for _, val := range slice {
 		if filterFn(val) {
 			outSlice = append(outSlice, val)

sliceutils_test.go

@@ -7,6 +7,10 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+////////////////////////////////
+//********** TESTS ***********//
+////////////////////////////////
+
 func TestAll(t *testing.T) {
 	t.Run("All elements evaluate to true", func(t *testing.T) {
 		slice := []int{1, 4, 6, 2, 3, 7}
@@ -695,3 +699,51 @@ func TestUnion(t *testing.T) {
 		assert.Nil(t, union)
 	})
 }
+
+////////////////////////////////
+//******** BENCHMARKS ********//
+////////////////////////////////
+
+func BenchmarkAll(b *testing.B) {
+	slice := []string{"boo", "bar", "baz", "hib", "heb", "obe", "lob", "suber",
+		"library", "functional function", "slice", "NOW", "hey"}
+
+	b.Run("Do all strings contain rune", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			var _ = All(slice, func(x string) bool { return strings.ContainsRune(x, rune('b')) })
+		}
+	})
+}
+
+func BenchmarkAny(b *testing.B) {
+	slice := []string{"foo", "bar", "baz", "his", "her", "one", "log", "super",
+		"library", "functional function", "slice", "NOW", "hey"}
+
+	b.Run("Does any string contain rune", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			var _ = Any(slice, func(x string) bool { return strings.ContainsRune(x, rune('W')) })
+		}
+	})
+}
+
+func BenchmarkFilter(b *testing.B) {
+	b.Run("Filter to include strings shorter than 4 characters", func(b *testing.B) {
+		slice := []string{"foo", "bar", "baz", "his", "her", "one", "log", "super",
+			"library", "functional function", "slice", "NOW", "hey"}
+
+		for i := 0; i < b.N; i++ {
+			var _ = Filter(slice, func(x string) bool { return len(x) < 4 })
+		}
+	})
+}
+
+func BenchmarkFilterInPlace(b *testing.B) {
+	b.Run("Filter in-place to include strings shorter than 4 characters", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			slice := []string{"foo", "bar", "baz", "his", "her", "one", "log", "super",
+				"library", "functional function", "slice", "NOW", "hey"}
+
+			FilterInPlace(&slice, func(x string) bool { return len(x) < 4 })
+		}
+	})
+}