reverse: tests

Author: pascal-blokur

.github/workflows/go.yaml

@@ -2,11 +2,10 @@ name: Go
 
 on:
   push:
-    branches: [main]
-  pull_request:
     branches:
       - *
 
+
 jobs:
   lint:
     runs-on: ubuntu-latest

replacer_test.go

@@ -3,6 +3,7 @@ package csvheaders_test
 import (
 	"bytes"
 	"encoding/csv"
+	"errors"
 	"slices"
 	"testing"
 
@@ -14,6 +15,7 @@ func TestReplacer(t *testing.T) {
 
 	t.Run("Read", testReplacerRead)
 	t.Run("ReadAll", testReplacerReadAll)
+	t.Run("Reverse", testReplacerReverse)
 }
 
 func testReplacerRead(t *testing.T) {
@@ -55,21 +57,20 @@ field 1,Charles,Monica
 func testReplacerReadAll(t *testing.T) {
 	t.Parallel()
 
-	var rawRows = []byte(`recording artist,title,isrc
-THE BEATLES,LET IT BE,US1239875
-recording artist,my band,FR789230987
+	var rawRows = []byte(`recording artist,title
+THE BEATLES,LET IT BE
+recording artist,my band
 `)
 
 	want := [][]string{
-		{"ARTIST", "TITLE", "ISRC"},
-		{"THE BEATLES", "LET IT BE", "US1239875"},
-		{"recording artist", "my band", "FR789230987"},
+		{"ARTIST", "TITLE"},
+		{"THE BEATLES", "LET IT BE"},
+		{"recording artist", "my band"},
 	}
 
 	headerReplacements := map[string]string{
 		"recording artist": "ARTIST",
 		"title":            "TITLE",
-		"isrc":             "ISRC",
 	}
 
 	r := csvheaders.NewReplacer(csv.NewReader(bytes.NewBuffer(rawRows)), headerReplacements)
@@ -79,6 +80,65 @@ recording artist,my band,FR789230987
 		t.Fatal(err)
 	}
 
+	compareResults(t, want, got)
+}
+
+func testReplacerReverse(t *testing.T) {
+	t.Parallel()
+
+	var rawRows = []byte(`field 1,field 2,field 10
+value 1,field 2,value 10
+`)
+
+	testCases := map[string]struct {
+		headerMapping map[string]string
+		expectedError error
+		want          [][]string
+	}{
+		"duplicated header": {
+			headerMapping: map[string]string{
+				"field 1": "FIELD",
+				"field 2": "FIELD",
+			},
+			expectedError: csvheaders.ErrDuplicateHeader,
+			want:          nil,
+		},
+		"nil headers": {
+			headerMapping: nil,
+			expectedError: nil,
+			want:          [][]string{{"field 1", "field 2", "field 10"}, {"value 1", "field 2", "value 10"}},
+		},
+		"no header conflict": {
+			headerMapping: map[string]string{"Monday": "field 10"},
+			expectedError: nil,
+			want:          [][]string{{"field 1", "field 2", "Monday"}, {"value 1", "field 2", "value 10"}},
+		},
+	}
+
+	for name, testCase := range testCases {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			r, err := csvheaders.NewReverseReplacer(csv.NewReader(bytes.NewBuffer(rawRows)), testCase.headerMapping)
+			if testCase.expectedError != nil {
+				if !errors.Is(err, testCase.expectedError) {
+					t.Fatalf("expected %s, got %s", testCase.expectedError, err)
+				}
+
+				return
+			}
+
+			got, err := r.ReadAll()
+			if err != nil {
+				t.Fatalf("unexpected error while reading: %s", err)
+			}
+
+			compareResults(t, testCase.want, got)
+		})
+	}
+}
+
+func compareResults(t *testing.T, want, got [][]string) {
 	if len(got) != len(want) {
 		t.Fatalf("got %d records, want %d", len(got), len(want))
 	}