first commit

scanner_test.go

@@ -0,0 +1,80 @@
+package settings
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"maps"
+	"math/rand"
+	"testing"
+)
+
+var (
+	KeyValuePairs = map[string]string{
+		"A": "a",
+		"B": "b",
+		"C": "c",
+	}
+)
+
+func RandomKeyValueDelimiter() byte {
+	return KeyValueDelimiterChars[rand.Intn(len(KeyValueDelimiterChars))]
+}
+
+func WriteMapToWriter(w io.Writer, m map[string]string) error {
+	writer := bufio.NewWriter(w)
+	comments := []string{"// this is a random comment", "# this is another random comment"}
+	randomComment := func() string { return comments[rand.Intn(len(comments))] }
+	var position int
+	for k, v := range m {
+		switch rand.Float64() >= .5 {
+		case true:
+			fmt.Fprintf(writer, "%s\n", randomComment())
+		}
+		fmt.Fprintf(writer, "%s%c%s", k, RandomKeyValueDelimiter(), v)
+		if position < len(m)-1 {
+			writer.WriteByte('\n')
+		}
+		position++
+	}
+	return writer.Flush()
+}
+
+func TestScannerParsesFilesProperly(t *testing.T) {
+	var buffer bytes.Buffer
+	err := WriteMapToWriter(&buffer, KeyValuePairs)
+	if err != nil {
+		t.Fatalf("error writing map to buffer: %v\n", err)
+	}
+	scanner := NewScanner(&buffer)
+	got := make(map[string]string)
+loop:
+	for {
+		key, value, err := scanner.ReadNextLine()
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				break loop
+			}
+			t.Fatalf("error reading next line from scanner: %v\n", err)
+		}
+		got[key] = value
+	}
+	if want := KeyValuePairs; !maps.Equal(want, got) {
+		t.Fatalf("error: wanted '%+v'; got '%+v'\n", want, got)
+	}
+}
+
+func TestScannerHandlesInvalidLinesProperly(t *testing.T) {
+	buffer := bytes.NewBufferString("validKey-validValue")
+	scanner := NewScanner(buffer)
+	key, value, err := scanner.ReadNextLine()
+	if !errors.Is(err, ErrNoValidDelimiter) {
+		t.Fatalf("error: wanted %v; got %v\n", ErrNoValidDelimiter, err)
+	} else if want, got := "", key; want != got {
+		t.Fatalf("error: wanted key '%s'; got '%s'\n", want, got)
+	} else if want, got := "", value; want != got {
+		t.Fatalf("error: wanted value '%s'; got '%s'\n", want, got)
+	}
+}