Improve test coverage.

Author: ChrisHines

stack.go

@@ -143,6 +143,14 @@ func (c Call) file() string {
 	return file
 }
 
+func (c Call) line() int {
+	if c.fn == nil {
+		return 0
+	}
+	_, line := c.fn.FileLine(c.pc)
+	return line
+}
+
 // CallStack records a sequence of function invocations from a goroutine
 // stack.
 type CallStack []Call

stack_test.go

@@ -87,6 +87,42 @@ func TestCallFormat(t *testing.T) {
 	}
 }
 
+func TestTrimAbove(t *testing.T) {
+	trace := trimAbove()
+	if got, want := len(trace), 2; got != want {
+		t.Errorf("got len(trace) == %v, want %v, trace: %n", got, want, trace)
+	}
+	if got, want := fmt.Sprintf("%n", trace[1]), "TestTrimAbove"; got != want {
+		t.Errorf("got %q, want %q", got, want)
+	}
+}
+
+func trimAbove() stack.CallStack {
+	call := stack.Caller(1)
+	trace := stack.Trace()
+	return trace.TrimAbove(call)
+}
+
+func TestTrimBelow(t *testing.T) {
+	trace := trimBelow()
+	if got, want := fmt.Sprintf("%n", trace[0]), "TestTrimBelow"; got != want {
+		t.Errorf("got %q, want %q", got, want)
+	}
+}
+
+func trimBelow() stack.CallStack {
+	call := stack.Caller(1)
+	trace := stack.Trace()
+	return trace.TrimBelow(call)
+}
+
+func TestTrimRuntime(t *testing.T) {
+	trace := stack.Trace().TrimRuntime()
+	if got, want := len(trace), 1; got != want {
+		t.Errorf("got len(trace) == %v, want %v, trace: %#v", got, want, trace)
+	}
+}
+
 func BenchmarkCallVFmt(b *testing.B) {
 	c := stack.Caller(0)
 	b.ResetTimer()
@@ -95,6 +131,12 @@ func BenchmarkCallVFmt(b *testing.B) {
 	}
 }
 
+func BenchmarkCallerAndVFmt(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		fmt.Fprint(ioutil.Discard, stack.Caller(0))
+	}
+}
+
 func BenchmarkCallPlusVFmt(b *testing.B) {
 	c := stack.Caller(0)
 	b.ResetTimer()
@@ -159,12 +201,30 @@ func BenchmarkCallPlusNFmt(b *testing.B) {
 	}
 }
 
+func BenchmarkCaller(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		stack.Caller(0)
+	}
+}
+
 func BenchmarkTrace(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		stack.Trace()
 	}
 }
 
+func BenchmarkFuncForPC(b *testing.B) {
+	pc, _, _, _ := runtime.Caller(0)
+	pc--
+	var fn *runtime.Func
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		fn = runtime.FuncForPC(pc)
+	}
+	b.StopTimer()
+	b.Log(fn.FileLine(pc))
+}
+
 func deepStack(depth int, b *testing.B) stack.CallStack {
 	if depth > 0 {
 		return deepStack(depth-1, b)

stackinternal_test.go

@@ -1,6 +1,9 @@
 package stack
 
-import "testing"
+import (
+	"runtime"
+	"testing"
+)
 
 func TestFindSigpanic(t *testing.T) {
 	t.Parallel()
@@ -9,3 +12,22 @@ func TestFindSigpanic(t *testing.T) {
 		t.Errorf("got == %v, want == %v", got, want)
 	}
 }
+
+func TestCaller(t *testing.T) {
+	t.Parallel()
+
+	c := Caller(0)
+	_, file, line, ok := runtime.Caller(0)
+	line--
+	if !ok {
+		t.Fatal("runtime.Caller(0) failed")
+	}
+
+	if got, want := c.file(), file; got != want {
+		t.Errorf("got file == %v, want file == %v", got, want)
+	}
+
+	if got, want := c.line(), line; got != want {
+		t.Errorf("got line == %v, want line == %v", got, want)
+	}
+}