fix: improve snapshot diff with newlines (#71)

remove extraneous newlines from snap diff
gkampitakis · Jul 9, 2023 · 09d3a05 · 09d3a05
1 parent 31d53b8
commit 09d3a05
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Showing 10 changed files with 158 additions and 29 deletions.
diff --git a/golangci.yml b/golangci.yml
@@ -9,14 +9,11 @@ linters:
     - gofumpt
     - revive
     - unconvert
-    - gocognit
 
   disable:
     - errcheck
 
 linters-settings:
-  gocognit:
-    min-complexity: 45
   lll:
     line-length: 130
   gofumpt:

diff --git a/snaps/__snapshots__/diff_test.snap b/snaps/__snapshots__/diff_test.snap
@@ -4,8 +4,8 @@
 [38;5;52m[48;5;225m- Snapshot    - 20[0m
 [38;5;22m[48;5;159m+ Received + 10000[0m
 
-mock-diff[2m
-at snap/path:10
+mock-diff
+[2mat snap/path:10
 [0m
 ---
 
@@ -14,8 +14,8 @@ at snap/path:10
 [38;5;52m[48;5;225m- Snapshot - 10000[0m
 [38;5;22m[48;5;159m+ Received    + 20[0m
 
-mock-diff[2m
-at snap/path:20
+mock-diff
+[2mat snap/path:20
 [0m
 ---
 
@@ -24,8 +24,10 @@ at snap/path:20
 [38;5;52m[48;5;225m- Snapshot - 20[0m
 [38;5;22m[48;5;159m+ Received + 20[0m
 
-[48;5;225m[38;5;52m- [0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;159m[38;5;22m+ [0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[2m
-at snap/path:10
+[48;5;225m[38;5;52m- [0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m[48;5;225m[38;5;52mabc[0m[48;5;127m[38;5;255md[0m
+[48;5;159m[38;5;22m+ [0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m[48;5;159m[38;5;22mabc[0m[48;5;23m[38;5;255mf[0m
+
+[2mat snap/path:10
 [0m
 ---
 
@@ -54,8 +56,8 @@ at snap/path:10
 [38;5;22m[48;5;159m+                                   Sed lorem felis, condimentum eget vehicula non, sagittis sit amet diam. [0m
 [38;5;22m[48;5;159m+                                   Vivamus ut sapien at erat imperdiet suscipit id a lectus.[0m
 [38;5;22m[48;5;159m+                                   Another Line added.[0m
-[2m
-at snap/path:10
+
+[2mat snap/path:10
 [0m
 ---
 
@@ -107,4 +109,85 @@ at snap/path:20
 [38;5;22m[48;5;159m+ Received + 10[0m
 
 there is a diff here
+
+---
+
+[TestDiff/should_print_newline_diffs/multiline - 1]
+
+[38;5;52m[48;5;225m- Snapshot - 0[0m
+[38;5;22m[48;5;159m+ Received + 3[0m
+
+  [2msnapshot
+[0m[38;5;22m[48;5;159m+ [0m
+  [2m         with multiple lines
+[0m[38;5;22m[48;5;159m+ [0m
+[38;5;22m[48;5;159m+          diff[0m
+  [2m                          
+[0m
+[2mat snap/path:10
+[0m
+---
+
+[TestDiff/should_print_newline_diffs/multiline - 2]
+
+[38;5;52m[48;5;225m- Snapshot - 3[0m
+[38;5;22m[48;5;159m+ Received + 0[0m
+
+  [2msnapshot
+[0m[38;5;52m[48;5;225m- [0m
+  [2m         with multiple lines
+[0m[38;5;52m[48;5;225m- [0m
+[38;5;52m[48;5;225m-          diff[0m
+  [2m                          
+[0m
+[2mat snap/path:10
+[0m
+---
+
+[TestDiff/should_print_newline_diffs/singleline - 1]
+
+[38;5;52m[48;5;225m- Snapshot - 0[0m
+[38;5;22m[48;5;159m+ Received + 1[0m
+
+[48;5;225m[38;5;52m- [0m[48;5;225m[38;5;52msingle line snap[0m
+[48;5;159m[38;5;22m+ [0m[48;5;159m[38;5;22msingle line snap[0m[48;5;23m[38;5;255m ↵[0m
+
+[2mat snap/path:10
+[0m
+---
+
+[TestDiff/should_print_newline_diffs/singleline - 2]
+
+[38;5;52m[48;5;225m- Snapshot - 0[0m
+[38;5;22m[48;5;159m+ Received + 1[0m
+
+[48;5;225m[38;5;52m- [0m[48;5;225m[38;5;52msingle line snap[0m
+[48;5;159m[38;5;22m+ [0m[48;5;159m[38;5;22msingle line snap[0m[48;5;23m[38;5;255m ↵[0m
+
+[2mat snap/path:10
+[0m
+---
+
+[TestDiff/should_print_newline_diffs/singleline - 3]
+
+[38;5;52m[48;5;225m- Snapshot - 0[0m
+[38;5;22m[48;5;159m+ Received + 1[0m
+
+[48;5;225m[38;5;52m- [0m[48;5;225m[38;5;52msingle line snap[0m
+[48;5;159m[38;5;22m+ [0m[48;5;159m[38;5;22msingle line snap[0m[48;5;23m[38;5;255m↵[0m
+
+[2mat snap/path:10
+[0m
+---
+
+[TestDiff/should_print_newline_diffs/singleline - 4]
+
+[38;5;52m[48;5;225m- Snapshot - 1[0m
+[38;5;22m[48;5;159m+ Received + 0[0m
+
+[48;5;225m[38;5;52m- [0m[48;5;225m[38;5;52msingle line snap[0m[48;5;127m[38;5;255m↵[0m
+[48;5;159m[38;5;22m+ [0m[48;5;159m[38;5;22msingle line snap[0m
+
+[2mat snap/path:10
+[0m
 ---
diff --git a/snaps/diff.go b/snaps/diff.go
@@ -34,6 +34,10 @@ func isSingleline(s string) bool {
 	return i == len(s)-1 || i == -1
 }
 
+func hasNewLine(b []byte) bool {
+	return b[len(b)-1] == '\n'
+}
+
 // shouldPrintHighlights checks if the two strings are going to be presented with
 // inline highlights
 func shouldPrintHighlights(a, b string) bool {
@@ -165,16 +169,31 @@ func singlelineDiff(expected, received string) (string, int, int) {
 		switch diff.Type {
 		case diffDelete:
 			deleted++
-			colors.FprintDeleteBold(a, diff.Text)
+			if strings.HasSuffix(diff.Text, "\n") {
+				colors.FprintDeleteBold(a, diff.Text[:len(diff.Text)-1]+newLineSymbol)
+			} else {
+				colors.FprintDeleteBold(a, diff.Text)
+			}
 		case diffInsert:
 			inserted++
-			colors.FprintInsertBold(b, diff.Text)
+			if strings.HasSuffix(diff.Text, "\n") {
+				colors.FprintInsertBold(b, diff.Text[:len(diff.Text)-1]+newLineSymbol)
+			} else {
+				colors.FprintInsertBold(b, diff.Text)
+			}
 		case diffEqual:
 			colors.FprintBg(a, colors.RedBg, colors.Reddiff, diff.Text)
 			colors.FprintBg(b, colors.GreenBG, colors.Greendiff, diff.Text)
 		}
 	}
 
+	if !hasNewLine(a.Bytes()) {
+		a.WriteByte('\n')
+	}
+	if !hasNewLine(b.Bytes()) {
+		b.WriteByte('\n')
+	}
+
 	a.Write(b.Bytes())
 
 	return a.String(), inserted, deleted
@@ -204,15 +223,16 @@ func buildDiffReport(inserted, deleted int, diff, name string, line int) string
 
 	iPadding, dPadding := intPadding(inserted, deleted)
 
-	s.WriteString("\n")
+	s.WriteByte('\n')
 	colors.FprintDelete(&s, fmt.Sprintf("Snapshot %s- %d\n", dPadding, deleted))
 	colors.FprintInsert(&s, fmt.Sprintf("Received %s+ %d\n", iPadding, inserted))
-	s.WriteString("\n")
+	s.WriteByte('\n')
 
 	s.WriteString(diff)
+	s.WriteByte('\n')
 
 	if name != "" {
-		colors.Fprint(&s, colors.Dim, fmt.Sprintf("\nat %s:%d\n", name, line))
+		colors.Fprint(&s, colors.Dim, fmt.Sprintf("at %s:%d\n", name, line))
 	}
 
 	return s.String()

diff --git a/snaps/diff_test.go b/snaps/diff_test.go
@@ -135,4 +135,32 @@ func TestDiff(t *testing.T) {
 			MatchSnapshot(t, prettyDiff(a, b, "snap/path", 20))
 		})
 	})
+
+	t.Run("should print newline diffs", func(t *testing.T) {
+		t.Run("multiline", func(t *testing.T) {
+			a := `snapshot
+			with multiple lines
+			`
+			b := `snapshot
+
+			with multiple lines
+
+			diff
+			`
+
+			MatchSnapshot(t, prettyDiff(a, b, "snap/path", 10))
+			MatchSnapshot(t, prettyDiff(b, a, "snap/path", 10))
+		})
+
+		t.Run("singleline", func(t *testing.T) {
+			a := "single line snap"
+			b := "single line snap \n"
+			c := "single line snap\n"
+
+			MatchSnapshot(t, prettyDiff(a, b, "snap/path", 10))
+			MatchSnapshot(t, prettyDiff(a, b, "snap/path", 10))
+			MatchSnapshot(t, prettyDiff(a, c, "snap/path", 10))
+			MatchSnapshot(t, prettyDiff(c, a, "snap/path", 10))
+		})
+	})
 }
diff --git a/snaps/matchJSON.go b/snaps/matchJSON.go
@@ -157,7 +157,7 @@ func validateJSON(input interface{}) ([]byte, error) {
 }
 
 func takeJSONSnapshot(b []byte) string {
-	return string(pretty.PrettyOptions(b, jsonOptions))
+	return strings.TrimSuffix(string(pretty.PrettyOptions(b, jsonOptions)), "\n")
 }
 
 func applyJSONMatchers(b []byte, matchers ...match.JSONMatcher) ([]byte, []match.MatcherError) {

diff --git a/snaps/matchJSON_test.go b/snaps/matchJSON_test.go
@@ -20,8 +20,7 @@ func TestMatchJSON(t *testing.T) {
   4
  ],
  "user": "mock-name"
-}
-`
+}`
 
 		for _, tc := range []struct {
 			name  string

diff --git a/snaps/matchSnapshot.go b/snaps/matchSnapshot.go
@@ -2,6 +2,7 @@ package snaps
 
 import (
 	"errors"
+	"strings"
 
 	"github.com/gkampitakis/go-snaps/internal/colors"
 	"github.com/kr/pretty"
@@ -110,5 +111,5 @@ func takeSnapshot(objects []interface{}) string {
 		snapshot += pretty.Sprint(objects[i]) + "\n"
 	}
 
-	return escapeEndChars(snapshot)
+	return strings.TrimSuffix(escapeEndChars(snapshot), "\n")
 }
diff --git a/snaps/matchSnapshot_test.go b/snaps/matchSnapshot_test.go
@@ -121,7 +121,7 @@ func TestMatchSnapshot(t *testing.T) {
 				expected := "\n\x1b[38;5;52m\x1b[48;5;225m- Snapshot - 2\x1b[0m\n\x1b[38;5;22m\x1b[48;5;159m" +
 					"+ Received + 2\x1b[0m\n\n\x1b[38;5;52m\x1b[48;5;225m- int(10)\x1b[0m\n\x1b[38;5;52m\x1b[48;5;225m" +
 					"- hello world\x1b[0m\n\x1b[38;5;22m\x1b[48;5;159m+ int(100)\x1b[0m\n\x1b[38;5;22m\x1b[48;5;159m" +
-					"+ bye world\x1b[0m\n  \x1b[2m↵\n\x1b[0m\x1b[2m\nat " + filepath.FromSlash(
+					"+ bye world\x1b[0m\n\n\x1b[2mat " + filepath.FromSlash(
 					"../__snapshots__/matchSnapshot_test.snap:2",
 				) +
 					"\n\x1b[0m"
@@ -221,7 +221,7 @@ func TestMatchSnapshot(t *testing.T) {
 					"+ Received + 3\x1b[0m\n\n\x1b[38;5;52m\x1b[48;5;225m- int(10)\x1b[0m\n\x1b[38;5;52m\x1b[48;5;225m" +
 					"- hello world----\x1b[0m\n\x1b[38;5;52m\x1b[48;5;225m- ---\x1b[0m\n\x1b[38;5;22m\x1b[48;5;159m" +
 					"+ int(100)\x1b[0m\n\x1b[38;5;22m\x1b[48;5;159m+ bye world----\x1b[0m\n\x1b[38;5;22m\x1b[48;5;159m" +
-					"+ --\x1b[0m\n  \x1b[2m↵\n\x1b[0m\x1b[2m\nat " + filepath.FromSlash(
+					"+ --\x1b[0m\n\n\x1b[2mat " + filepath.FromSlash(
 					"../__snapshots__/matchSnapshot_test.snap:2",
 				) +
 					"\n\x1b[0m"

diff --git a/snaps/snapshot.go b/snaps/snapshot.go
@@ -129,7 +129,7 @@ func getPrevSnapshot(testID, snapPath string) (string, int, error) {
 			line := s.Bytes()
 
 			if bytes.Equal(line, endSequenceByteSlice) {
-				return snapshot.String(), lineNumber, nil
+				return strings.TrimSuffix(snapshot.String(), "\n"), lineNumber, nil
 			}
 			snapshot.Write(line)
 			snapshot.WriteByte('\n')
@@ -150,7 +150,7 @@ func addNewSnapshot(testID, snapshot, snapPath string) error {
 	}
 	defer f.Close()
 
-	_, err = fmt.Fprintf(f, "\n%s\n%s---\n", testID, snapshot)
+	_, err = fmt.Fprintf(f, "\n%s\n%s\n---\n", testID, snapshot)
 	return err
 }
 
@@ -185,6 +185,7 @@ func updateSnapshot(testID, snapshot, snapPath string) error {
 
 		// add new snapshot
 		updatedSnapFile.WriteString(snapshot)
+		updatedSnapFile.WriteByte('\n')
 		updatedSnapFile.Write(endSequenceByteSlice)
 		updatedSnapFile.WriteByte('\n')
 	}

diff --git a/snaps/snapshot_test.go b/snaps/snapshot_test.go
@@ -76,21 +76,21 @@ func TestGetPrevSnapshot(t *testing.T) {
 			description: "should return match",
 			testID:      "[my-test - 1]",
 			fileData:    "[my-test - 1]\nmysnapshot\n---\n",
-			snap:        "mysnapshot\n",
+			snap:        "mysnapshot",
 			line:        1,
 		},
 		{
 			description: "should ignore regex in testID and match correct snap",
 			testID:      "[.*]",
 			fileData:    "\n[my-test]\nwrong snap\n---\n\n[.*]\nmysnapshot\n---\n",
-			snap:        "mysnapshot\n",
+			snap:        "mysnapshot",
 			line:        6,
 		},
 		{
 			description: "should ignore end chars (---) inside snapshot",
 			testID:      "[mock-test 1]",
 			fileData:    "\n[mock-test 1]\nmysnapshot\n---moredata\n---\n",
-			snap:        "mysnapshot\n---moredata\n",
+			snap:        "mysnapshot\n---moredata",
 			line:        2,
 		},
 	} {
@@ -111,7 +111,7 @@ func TestGetPrevSnapshot(t *testing.T) {
 func TestAddNewSnapshot(t *testing.T) {
 	snapPath := filepath.Join(t.TempDir(), "__snapshots__/mock-test.snap")
 
-	test.NoError(t, addNewSnapshot("[mock-id]", "my-snap\n", snapPath))
+	test.NoError(t, addNewSnapshot("[mock-id]", "my-snap", snapPath))
 	test.Equal(t, "\n[mock-id]\nmy-snap\n---\n", test.GetFileContent(t, snapPath))
 }
 
@@ -198,7 +198,7 @@ string hello world 1 3 2
 
 `
 	snapPath := test.CreateTempFile(t, mockSnap)
-	newSnapshot := "int(1250)\nstring new value\n"
+	newSnapshot := "int(1250)\nstring new value"
 
 	test.NoError(t, updateSnapshot("[Test_3/TestSimple - 1]", newSnapshot, snapPath))
 	test.Equal(t, updatedSnap, test.GetFileContent(t, snapPath))
-Original file line number
+Diff line change
@@ Expand Up / @@ -20,8 +20,7 @@ func TestMatchJSON(t *testing.T) { @@
      ],
      "user": "mock-name"
-    }
-    `
+    }`
     		for _, tc := range []struct {
     			name  string
@@ Expand Down @@