lib/test: refactoring, rename TestWriter to BufferWriter

The name TestWriter is considered stutter if its called from external
package, test.TestWriter.

While at it, implement the Error and Errorf in BufferWriter and add
comment to each exported methods.

5 files changed, 49 insertions, 22 deletions

diff --git a/lib/test/example_test.go b/lib/test/example_test.go
index efd36eea..0835509a 100644
--- a/lib/test/example_test.go
+++ b/lib/test/example_test.go
@@ -60,7 +60,7 @@ func ExampleAssert_struct() {
 	}}
 
 	var (
-		tw = test.TestWriter{}
+		tw = test.BufferWriter{}
 	)
 
 	for _, c := range cases {
@@ -77,7 +77,8 @@ func ExampleAssert_struct() {
 
 func ExampleAssert_string() {
 	var (
-		tw  = test.TestWriter{}
+		tw = test.BufferWriter{}
+
 		exp string
 		got string
 	)
@@ -87,8 +88,8 @@ func ExampleAssert_string() {
 	test.Assert(&tw, ``, exp, got)
 	fmt.Println(tw.String())
 
-	exp = `func (tw *TestWriter) Fatal(args ...any)                 { fmt.Fprint(tw, args...) }`
-	got = `func (tw *TestWriter) Fatalf(format string, args ...any) { fmt.Fprintf(tw, format, args...) }`
+	exp = `func (tw *BufferWriter) Fatal(args ...any)                 { fmt.Fprint(tw, args...) }`
+	got = `func (tw *BufferWriter) Fatalf(format string, args ...any) { fmt.Fprintf(tw, format, args...) }`
 	tw.Reset()
 	test.Assert(&tw, ``, exp, got)
 	fmt.Println(tw.String())
@@ -96,13 +97,14 @@ func ExampleAssert_string() {
 	// !!! Assert: expecting string(a string), got string(b string)
 	// !!! :
 	// --++
-	// 0 - func (tw *TestWriter) Fatal(args ...any)                 { fmt.Fprint(tw, args...) }
-	// 0 + func (tw *TestWriter) Fatalf(format string, args ...any) { fmt.Fprintf(tw, format, args...) }
+	// 0 - func (tw *BufferWriter) Fatal(args ...any)                 { fmt.Fprint(tw, args...) }
+	// 0 + func (tw *BufferWriter) Fatalf(format string, args ...any) { fmt.Fprintf(tw, format, args...) }
 }
 
 func ExampleAssert_string2() {
 	var (
-		tw  = test.TestWriter{}
+		tw = test.BufferWriter{}
+
 		exp string
 		got string
 	)
diff --git a/lib/test/test.go b/lib/test/test.go
index 734c7e20..587242fe 100644
--- a/lib/test/test.go
+++ b/lib/test/test.go
@@ -38,7 +38,7 @@ func printStackTrace(w Writer, trace []byte) {
 		}
 	}
 
-	_, ok = w.(*TestWriter)
+	_, ok = w.(*BufferWriter)
 	if !ok {
 		w.Log("\n!!! ERR " + string(trace[start:end]))
 	}
diff --git a/lib/test/test_test.go b/lib/test/test_test.go
index ff2b4a6f..3fb4bdd0 100644
--- a/lib/test/test_test.go
+++ b/lib/test/test_test.go
@@ -27,17 +27,17 @@ func TestAssert(t *testing.T) {
 
 	var (
 		c   testCase
-		tw  TestWriter
+		bw  BufferWriter
 		got string
 	)
 
 	for _, c = range cases {
-		Assert(&tw, ``, c.a, c.b)
-		got = tw.String()
+		Assert(&bw, ``, c.a, c.b)
+		got = bw.String()
 		if c.exp != got {
 			t.Fatalf(`want: %s, got: %s`, c.exp, got)
 		}
 
-		tw.Reset()
+		bw.Reset()
 	}
 }
diff --git a/lib/test/test_writer.go b/lib/test/test_writer.go
index a778e297..676582f8 100644
--- a/lib/test/test_writer.go
+++ b/lib/test/test_writer.go
@@ -9,14 +9,39 @@ import (
 	"fmt"
 )
 
-// TestWriter write Errorx, Fatalx, and Logx to bytes.Buffer.
-type TestWriter struct {
+// BufferWriter implement the Writer interface.
+// Any call to ErrorXxx, FatalXxx, and LogXxx will write to embedded
+// bytes.Buffer.
+type BufferWriter struct {
 	bytes.Buffer
 }
 
-func (tw *TestWriter) Error(args ...any)                 {}
-func (tw *TestWriter) Errorf(format string, args ...any) {}
-func (tw *TestWriter) Fatal(args ...any)                 { fmt.Fprint(tw, args...) }
-func (tw *TestWriter) Fatalf(format string, args ...any) { fmt.Fprintf(tw, format, args...) }
-func (tw *TestWriter) Log(args ...any)                   { fmt.Fprint(tw, args...) }
-func (tw *TestWriter) Logf(format string, args ...any)   { fmt.Fprintf(tw, format, args...) }
+// Error write the arguments into buffer.
+func (bw *BufferWriter) Error(args ...any) {
+	fmt.Fprintln(bw, args...)
+}
+
+// Errorf write formatted string with arguments into buffer.
+func (bw *BufferWriter) Errorf(format string, args ...any) {
+	fmt.Fprintf(bw, format, args...)
+}
+
+// Fatal write the arguments to buffer.
+func (bw *BufferWriter) Fatal(args ...any) {
+	fmt.Fprint(bw, args...)
+}
+
+// Fatalf write formatted string with arguments into buffer.
+func (bw *BufferWriter) Fatalf(format string, args ...any) {
+	fmt.Fprintf(bw, format, args...)
+}
+
+// Log write the arguments into buffer.
+func (bw *BufferWriter) Log(args ...any) {
+	fmt.Fprint(bw, args...)
+}
+
+// Logf write formatted string with arguments into buffer.
+func (bw *BufferWriter) Logf(format string, args ...any) {
+	fmt.Fprintf(bw, format, args...)
+}
diff --git a/lib/test/writer.go b/lib/test/writer.go
index 4ab2a4e2..19dddb97 100644
--- a/lib/test/writer.go
+++ b/lib/test/writer.go
@@ -4,8 +4,8 @@
 
 package test
 
-// Writer contains common methods between testing.T and testing.B, a subset of
-// testing.TB that cannot be used do private method.
+// Writer contains common methods between testing.T and testing.B, a subset
+// of testing.TB that cannot be used due to private methods.
 type Writer interface {
 	Error(args ...any)
 	Errorf(format string, args ...any)