[BEAM-13910] Improve coverage of gcsx package (#16942)

sdks/go/pkg/beam/util/gcsx/example_test.go

@@ -0,0 +1,47 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License.  You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package gcsx_test
+
+import (
+	"context"
+	"time"
+
+	"cloud.google.com/go/storage"
+	"github.com/apache/beam/sdks/v2/go/pkg/beam/util/gcsx"
+)
+
+func Example() {
+	ctx := context.Background()
+	c, err := gcsx.NewClient(ctx, storage.ScopeReadOnly)
+	if err != nil {
+		// do something
+	}
+
+	buckets, object, err := gcsx.ParseObject("gs://some-bucket/some-object")
+	if err != nil {
+		// do something
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	defer cancel()
+
+	bytes, err := gcsx.ReadObject(ctx, c, buckets, object)
+	if err != nil {
+		// do something
+	}
+
+	_ = bytes
+}

sdks/go/pkg/beam/util/gcsx/gcs_test.go

@@ -13,35 +13,86 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package gcsx_test
+package gcsx
 
 import (
-	"context"
-	"time"
+	"strings"
+	"testing"
 
-	"cloud.google.com/go/storage"
-	"github.com/apache/beam/sdks/v2/go/pkg/beam/util/gcsx"
+	"github.com/apache/beam/sdks/v2/go/pkg/beam/internal/errors"
 )
 
-func Example() {
-	ctx := context.Background()
-	c, err := gcsx.NewClient(ctx, storage.ScopeReadOnly)
-	if err != nil {
-		// do something
+func TestMakeObject(t *testing.T) {
+	if got, want := MakeObject("some-bucket", "some/path"), "gs://some-bucket/some/path"; got != want {
+		t.Fatalf("MakeObject() Got: %v Want: %v", got, want)
 	}
+}
 
-	buckets, object, err := gcsx.ParseObject("gs://some-bucket/some-object")
-	if err != nil {
-		// do something
+func TestParseObject(t *testing.T) {
+	tests := []struct {
+		object string
+		bucket string
+		path   string
+		err    error
+	}{
+		{
+			object: "gs://some-bucket/some-object",
+			bucket: "some-bucket",
+			path:   "some-object",
+			err:    nil,
+		},
+		{
+			object: "gs://some-bucket",
+			bucket: "some-bucket",
+			path:   "",
+			err:    nil,
+		},
+		{
+			object: "gs://",
+			bucket: "",
+			path:   "",
+			err:    errors.Errorf("object gs:// must have bucket"),
+		},
+		{
+			object: "other://some-bucket/some-object",
+			bucket: "",
+			path:   "",
+			err:    errors.Errorf("object other://some-bucket/some-object must have 'gs' scheme"),
+		},
 	}
 
-	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
-	defer cancel()
-
-	bytes, err := gcsx.ReadObject(ctx, c, buckets, object)
-	if err != nil {
-		// do something
+	for _, test := range tests {
+		if bucket, path, err := ParseObject(test.object); bucket != test.bucket || path != test.path || (err != nil && test.err == nil) || (err == nil && test.err != nil) {
+			t.Errorf("ParseObject(%v) Got: %v, %v, %v Want: %v, %v, %v", test.object, bucket, path, err, test.bucket, test.path, test.err)
+		}
 	}
+}
 
-	_ = bytes
+func TestJoin(t *testing.T) {
+	tests := []struct {
+		object string
+		elms   []string
+		result string
+	}{
+		{
+			object: "gs://some-bucket/some-object",
+			elms:   []string{"some/path", "more/pathing"},
+			result: "gs://some-bucket/some-object/some/path/more/pathing",
+		},
+		{
+			object: "gs://some-bucket/some-object",
+			elms:   []string{"some/path"},
+			result: "gs://some-bucket/some-object/some/path",
+		},
+		{
+			object: "gs://some-bucket/some-object",
+			elms:   []string{},
+			result: "gs://some-bucket/some-object",
+		},
+	}
+	for _, test := range tests {
+		if got, want := Join(test.object, test.elms...), test.result; got != want {
+			t.Errorf("Join(%v, %v) Got: %v Want: %v", test.object, strings.Join(test.elms, ", "), got, want)
+		}
+	}
 }