add tests and fix bugs accordingly

.gitignore

@@ -1,3 +1,4 @@
 measurements.txt
+measurements.out
 trace*
-.DS_store
+.DS_store

go.mod

@@ -1,3 +1,10 @@
 module github.com/shraddhaag/1brc-go
 
-go 1.20
+go 1.21
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.8.4 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,9 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"cmp"
 	"errors"
 	"flag"
 	"fmt"
@@ -11,15 +12,17 @@ import (
 	"runtime"
 	"runtime/pprof"
 	"runtime/trace"
-	"sort"
 	"strconv"
 	"strings"
 	"sync"
+
+	"slices"
 )
 
 var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to `file`")
 var memprofile = flag.String("memprofile", "", "write memory profile to `file`")
 var executionprofile = flag.String("execprofile", "", "write tarce execution to `file`")
+var input = flag.String("input", "", "path to the input file to evaluate")
 
 func main() {
 
@@ -47,7 +50,7 @@ func main() {
 		defer pprof.StopCPUProfile()
 	}
 
-	fmt.Println(evaluate())
+	fmt.Println(evaluate(*input))
 
 	if *memprofile != "" {
 		f, err := os.Create("./profiles/" + *memprofile)
@@ -62,30 +65,36 @@ func main() {
 	}
 }
 
-func evaluate() string {
+type result struct {
+	city string
+	temp string
+}
+
+func evaluate(input string) string {
 	// mapOfTemp, err := readFileLineByLineIntoAMap("./test_cases/measurements-rounding.txt")
-	mapOfTemp, err := readFileLineByLineIntoAMap("measurements.txt")
+	// mapOfTemp, err := readFileLineByLineIntoAMap("measurements.txt")
+	mapOfTemp, err := readFileLineByLineIntoAMap(input)
 	if err != nil {
 		panic(err)
 	}
 
-	var result []string
+	var resultArr []result
 	var wg sync.WaitGroup
 	var mx sync.Mutex
 
-	updateResult := func(input string) {
+	updateResult := func(city, temp string) {
 		mx.Lock()
 		defer mx.Unlock()
 
-		result = append(result, input)
+		resultArr = append(resultArr, result{city, temp})
 	}
 
 	for city, temps := range mapOfTemp {
 		wg.Add(1)
 		go func(city string, temps []float64) {
 			defer wg.Done()
 			var min, max, avg float64
-			min, max = math.MaxFloat64, 0
+			min, max = math.MaxFloat64, math.MinInt64
 
 			for _, temp := range temps {
 				if temp < min {
@@ -101,14 +110,21 @@ func evaluate() string {
 			avg = avg / float64(len(temps))
 			avg = math.Ceil(avg*10) / 10
 
-			updateResult(fmt.Sprintf("%s=%.1f/%.1f/%.1f", city, min, avg, max))
+			updateResult(city, fmt.Sprintf("%.1f/%.1f/%.1f", min, avg, max))
 
 		}(city, temps)
 	}
 
 	wg.Wait()
-	sort.Strings(result)
-	return strings.Join(result, ", ")
+	slices.SortFunc(resultArr, func(i, j result) int {
+		return cmp.Compare(i.city, j.city)
+	})
+
+	var stringsBuilder strings.Builder
+	for _, i := range resultArr {
+		stringsBuilder.WriteString(fmt.Sprintf("%s=%s, ", i.city, i.temp))
+	}
+	return stringsBuilder.String()[:stringsBuilder.Len()-2]
 }
 
 func readFileLineByLineIntoAMap(filepath string) (map[string][]float64, error) {

main_test.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMain(t *testing.T) {
+
+	inputFiles := find("./test_cases", ".txt")
+	for _, test := range inputFiles {
+		t.Run(test, func(t *testing.T) {
+			output := evaluate(test + ".txt")
+			assert.Equal(t, readFile(test+".out"), "{"+output+"}\n")
+		})
+	}
+}
+
+func readFile(input string) string {
+	fileContent, err := os.ReadFile(input)
+	if err != nil {
+		panic(err)
+	}
+	return string(fileContent)
+}
+
+func find(root, ext string) []string {
+	var a []string
+	filepath.WalkDir(root, func(s string, d fs.DirEntry, e error) error {
+		if e != nil {
+			return e
+		}
+		if filepath.Ext(d.Name()) == ext {
+			a = append(a, s[:len(s)-len(ext)])
+		}
+		return nil
+	})
+	return a
+}