presubmit tests (#3630)

* presubmit tests

Rename the test file to presubmit_test.go
Remove println from previous merge.
Add filename hyphen check
Remove the shell presubmit file that did this before

Signed-off-by: Miek Gieben <miek@miek.nl>

* remove

Signed-off-by: Miek Gieben <miek@miek.nl>

test/presubmit_test.go

@@ -0,0 +1,77 @@
+package test
+
+// These tests check for meta level items, like trailing whitespace, correct file naming etc.
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"unicode"
+)
+
+func TestTrailingWhitespace(t *testing.T) {
+	err := filepath.Walk("..", hasTrailingWhitespace)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func hasTrailingWhitespace(path string, info os.FileInfo, _ error) error {
+	// Only handle regular files, skip files that are executable and skip file in the
+	// root that start with a .
+	if !info.Mode().IsRegular() {
+		return nil
+	}
+	if info.Mode().Perm()&0111 != 0 {
+		return nil
+	}
+	if strings.HasPrefix(path, "../.") {
+		return nil
+	}
+
+	file, err := os.Open(path)
+	if err != nil {
+		return nil
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		text := scanner.Text()
+		trimmed := strings.TrimRightFunc(text, unicode.IsSpace)
+		if len(text) != len(trimmed) {
+			return fmt.Errorf("file %q has trailing whitespace, text: %q", path, text)
+		}
+	}
+
+	return scanner.Err()
+}
+
+func TestFileNameHyphen(t *testing.T) {
+	err := filepath.Walk("..", hasHyphen)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func hasHyphen(path string, info os.FileInfo, _ error) error {
+	// only for regular files, not starting with a . and those that are go files.
+	if !info.Mode().IsRegular() {
+		return nil
+	}
+	if strings.HasPrefix(path, "../.") {
+		return nil
+	}
+	if filepath.Ext(path) != ".go" {
+		return nil
+	}
+
+	if strings.Index(path, "-") > 0 {
+		return fmt.Errorf("file %q has a hyphen, please use underscores in file names", path)
+	}
+
+	return nil
+}