1 files changed, 92 insertions, 0 deletions
diff --git a/src/internal/coverage/cformat/fmt_test.go b/src/internal/coverage/cformat/fmt_test.go
new file mode 100644
index 0000000..4d6da44
--- /dev/null
+++ b/src/internal/coverage/cformat/fmt_test.go
@@ -0,0 +1,92 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cformat_test
+
+import (
+	"internal/coverage"
+	"internal/coverage/cformat"
+	"strings"
+	"testing"
+)
+
+func TestBasics(t *testing.T) {
+	fm := cformat.NewFormatter(coverage.CtrModeAtomic)
+	fm.SetPackage("my/pack")
+
+	mku := func(stl, enl, nx uint32) coverage.CoverableUnit {
+		return coverage.CoverableUnit{
+			StLine:  stl,
+			EnLine:  enl,
+			NxStmts: nx,
+		}
+	}
+	fn1units := []coverage.CoverableUnit{
+		mku(10, 11, 2),
+		mku(15, 11, 1),
+	}
+	fn2units := []coverage.CoverableUnit{
+		mku(20, 25, 3),
+		mku(30, 31, 2),
+		mku(33, 40, 7),
+	}
+	fn3units := []coverage.CoverableUnit{
+		mku(99, 100, 1),
+	}
+	for k, u := range fn1units {
+		fm.AddUnit("p.go", "f1", false, u, uint32(k))
+	}
+	for k, u := range fn2units {
+		fm.AddUnit("q.go", "f2", false, u, 0)
+		fm.AddUnit("q.go", "f2", false, u, uint32(k))
+	}
+	for _, u := range fn3units {
+		fm.AddUnit("lit.go", "f3", true, u, 0)
+	}
+
+	var b1, b2, b3 strings.Builder
+	if err := fm.EmitTextual(&b1); err != nil {
+		t.Fatalf("EmitTextual returned %v", err)
+	}
+	wantText := strings.TrimSpace(`
+mode: atomic
+lit.go:99.0,100.0 1 0
+p.go:10.0,11.0 2 0
+p.go:15.0,11.0 1 1
+q.go:20.0,25.0 3 0
+q.go:30.0,31.0 2 1
+q.go:33.0,40.0 7 2`)
+	gotText := strings.TrimSpace(b1.String())
+	if wantText != gotText {
+		t.Errorf("emit text: got:\n%s\nwant:\n%s\n", gotText, wantText)
+	}
+
+	if err := fm.EmitPercent(&b2, "", false); err != nil {
+		t.Fatalf("EmitPercent returned %v", err)
+	}
+	wantPercent := strings.TrimSpace(`
+my/pack	coverage: 62.5% of statements
+`)
+	gotPercent := strings.TrimSpace(b2.String())
+	if wantPercent != gotPercent {
+		t.Errorf("emit percent: got:\n%s\nwant:\n%s\n", gotPercent, wantPercent)
+	}
+
+	if err := fm.EmitFuncs(&b3); err != nil {
+		t.Fatalf("EmitFuncs returned %v", err)
+	}
+	wantFuncs := strings.TrimSpace(`
+p.go:10:	f1		33.3%
+q.go:20:	f2		75.0%
+total		(statements)	62.5%`)
+	gotFuncs := strings.TrimSpace(b3.String())
+	if wantFuncs != gotFuncs {
+		t.Errorf("emit funcs: got:\n%s\nwant:\n%s\n", gotFuncs, wantFuncs)
+	}
+	if false {
+		t.Logf("text is %s\n", b1.String())
+		t.Logf("perc is %s\n", b2.String())
+		t.Logf("funcs is %s\n", b3.String())
+	}
+}