[BEAM-13907] Improve coverage of textio package (#16937)

sdks/go/pkg/beam/io/textio/sdf_test.go

@@ -28,9 +28,19 @@ import (
 // outputs the correct number of lines for it, even for an exceedingly long
 // line.
 func TestReadSdf(t *testing.T) {
-	f := "../../../../data/textio_test.txt"
 	p, s := beam.NewPipelineWithRoot()
-	lines := ReadSdf(s, f)
+	lines := ReadSdf(s, testFilePath)
+	passert.Count(s, lines, "NumLines", 1)
+
+	if _, err := beam.Run(context.Background(), "direct", p); err != nil {
+		t.Fatalf("Failed to execute job: %v", err)
+	}
+}
+
+func TestReadAllSdf(t *testing.T) {
+	p, s := beam.NewPipelineWithRoot()
+	files := beam.Create(s, testFilePath)
+	lines := ReadAllSdf(s, files)
 	passert.Count(s, lines, "NumLines", 1)
 
 	if _, err := beam.Run(context.Background(), "direct", p); err != nil {

sdks/go/pkg/beam/io/textio/textio_test.go

@@ -17,20 +17,25 @@
 package textio
 
 import (
+	"errors"
+	"os"
 	"testing"
 
+	"github.com/apache/beam/sdks/v2/go/pkg/beam"
 	_ "github.com/apache/beam/sdks/v2/go/pkg/beam/io/filesystem/local"
+	"github.com/apache/beam/sdks/v2/go/pkg/beam/testing/passert"
+	"github.com/apache/beam/sdks/v2/go/pkg/beam/testing/ptest"
 )
 
-func TestRead(t *testing.T) {
-	f := "../../../../data/textio_test.txt"
+const testFilePath = "../../../../data/textio_test.txt"
 
+func TestReadFn(t *testing.T) {
 	receivedLines := []string{}
 	getLines := func(line string) {
 		receivedLines = append(receivedLines, line)
 	}
 
-	err := readFn(nil, f, getLines)
+	err := readFn(nil, testFilePath, getLines)
 	if err != nil {
 		t.Fatalf("failed with %v", err)
 	}
@@ -40,3 +45,63 @@ func TestRead(t *testing.T) {
 	}
 
 }
+
+func TestRead(t *testing.T) {
+	p, s := beam.NewPipelineWithRoot()
+	lines := Read(s, testFilePath)
+	passert.Count(s, lines, "NumLines", 1)
+
+	ptest.RunAndValidate(t, p)
+}
+
+func TestReadAll(t *testing.T) {
+	p, s, files := ptest.CreateList([]string{testFilePath})
+	lines := ReadAll(s, files)
+	passert.Count(s, lines, "NumLines", 1)
+
+	ptest.RunAndValidate(t, p)
+}
+
+func TestWrite(t *testing.T) {
+	out := "text.txt"
+	p, s := beam.NewPipelineWithRoot()
+	lines := Read(s, testFilePath)
+	Write(s, out, lines)
+
+	ptest.RunAndValidate(t, p)
+
+	if _, err := os.Stat(out); errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("Failed to write %v", out)
+	}
+	t.Cleanup(func() {
+		os.Remove(out)
+	})
+
+	outfileContents, _ := os.ReadFile(out)
+	infileContents, _ := os.ReadFile(testFilePath)
+	if got, want := string(outfileContents), string(infileContents); got != want {
+		t.Fatalf("Write() wrote the wrong contents. Got: %v Want: %v", got, want)
+	}
+}
+
+func TestImmediate(t *testing.T) {
+	f, err := os.CreateTemp("", "test2.txt")
+	if err != nil {
+		t.Fatalf("Failed to create temp file, err: %v", err)
+	}
+	t.Cleanup(func() {
+		os.Remove(f.Name())
+	})
+	if err := os.WriteFile(f.Name(), []byte("hello\ngo\n"), 0644); err != nil {
+		t.Fatalf("Failed to write file %v, err: %v", f, err)
+	}
+
+	p, s := beam.NewPipelineWithRoot()
+	lines, err := Immediate(s, f.Name())
+	if err != nil {
+		t.Fatalf("Failed to insert Immediate: %v", err)
+	}
+	passert.Count(s, lines, "NumLines", 2)
+
+	ptest.RunAndValidate(t, p)
+}