feat: snapshot with environment variable update

bromide.go

@@ -0,0 +1,89 @@
+package bromide
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/hexops/valast"
+	"github.com/sergi/go-diff/diffmatchpatch"
+)
+
+const folder = "snapshots"
+
+func Snapshot[K comparable](t *testing.T, item K) {
+	t.Helper()
+
+	update := false
+	if u := os.Getenv("UPDATE_SNAPSHOTS"); u != "" {
+		v, err := strconv.ParseBool(u)
+		if err != nil {
+			t.Errorf("unable to parse boolean : %s", err.Error())
+			return
+		}
+
+		update = v
+	}
+
+	currentDir, err := os.Getwd()
+	if err != nil {
+		t.Errorf("Error getting current directory: %v", err)
+	}
+
+	snapshotDir := fmt.Sprintf("%s/%s", currentDir, folder)
+	name := fmt.Sprintf("%s/%s.snap", snapshotDir, t.Name())
+
+	incoming := serialize(item)
+
+	if err := os.MkdirAll(snapshotDir, 0755); err != nil {
+		panic("unable to create snapshot directory")
+	}
+
+	file, err := os.Open(name)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			panic("unable to open existing snapshot")
+		}
+
+		file, err := os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0644)
+		if err != nil {
+			panic("unable to create new snapshot" + err.Error())
+		}
+		defer file.Close()
+
+		if _, err := file.WriteString(incoming); err != nil {
+			panic("unable to create new snapshot")
+		}
+
+		t.Errorf("created snapshot")
+		return
+	}
+	defer file.Close()
+
+	existing := new(strings.Builder)
+	io.Copy(existing, file)
+
+	if existing.String() != incoming {
+		dmp := diffmatchpatch.New()
+
+		diffs := dmp.DiffMain(existing.String(), incoming, true)
+
+		t.Log("snapshot does not match")
+		t.Log(dmp.DiffPrettyText(diffs))
+
+		if update {
+			os.WriteFile(name, []byte(incoming), 0644)
+			return
+		}
+
+		t.Fail()
+		return
+	}
+}
+
+func serialize[K any](item K) string {
+	return valast.StringWithOptions(item, &valast.Options{Unqualify: false})
+}

bromide_test.go

@@ -0,0 +1,20 @@
+package bromide_test
+
+import (
+	"testing"
+
+	"github.com/cobbinma/bromide"
+)
+
+type testStruct struct {
+	example string
+	again   int
+}
+
+func Test_Snapshot(t *testing.T) {
+	hello := testStruct{
+		example: "hello",
+		again:   5,
+	}
+	bromide.Snapshot(t, hello)
+}

go.mod

@@ -0,0 +1,13 @@
+module github.com/cobbinma/bromide
+
+go 1.22.0
+
+require (
+	github.com/google/go-cmp v0.5.9 // indirect
+	github.com/hexops/valast v1.4.4 // indirect
+	github.com/sergi/go-diff v1.3.1 // indirect
+	golang.org/x/mod v0.7.0 // indirect
+	golang.org/x/sys v0.3.0 // indirect
+	golang.org/x/tools v0.4.0 // indirect
+	mvdan.cc/gofumpt v0.4.0 // indirect
+)

go.sum

@@ -0,0 +1,26 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/hexops/valast v1.4.4 h1:rETyycw+/L2ZVJHHNxEBgh8KUn+87WugH9MxcEv9PGs=
+github.com/hexops/valast v1.4.4/go.mod h1:Jcy1pNH7LNraVaAZDLyv21hHg2WBv9Nf9FL6fGxU7o4=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sergi/go-diff v1.3.1 h1:xkr+Oxo4BOQKmkn/B9eMK0g5Kg/983T9DqqPHwYqD+8=
+github.com/sergi/go-diff v1.3.1/go.mod h1:aMJSSKb2lpPvRNec0+w3fl7LP9IOFzdc9Pa4NFbPK1I=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+golang.org/x/mod v0.7.0 h1:LapD9S96VoQRhi/GrNTqeBJFrUjs5UHCAtTlgwA5oZA=
+golang.org/x/mod v0.7.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/sys v0.3.0 h1:w8ZOecv6NaNa/zC8944JTU3vz4u6Lagfk4RPQxv92NQ=
+golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/tools v0.4.0 h1:7mTAgkunk3fr4GAloyyCasadO6h9zSsQZbwvcaIciV4=
+golang.org/x/tools v0.4.0/go.mod h1:UE5sM2OK9E/d67R0ANs2xJizIymRP5gJU295PvKXxjQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+mvdan.cc/gofumpt v0.4.0 h1:JVf4NN1mIpHogBj7ABpgOyZc65/UUOkKQFkoURsz4MM=
+mvdan.cc/gofumpt v0.4.0/go.mod h1:PljLOHDeZqgS8opHRKLzp2It2VBuSdteAgqUfzMTxlQ=

snapshots/Test_Snapshot.snap

@@ -0,0 +1 @@
+testStruct{example: "hello", again: 5}