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>

.presubmit/filename-hyphen

-#!/usr/bin/env bash
-
-echo "** presubmit/$(basename $0)"
-
-for dir in "$@"; do
-    if find $dir | grep '-'; then
-        echo "** presubmit/$(basename $0): please use an underscore in filenames instead of a hyphen"
-        exit 1
-    fi
-done

test/trailing_test.go → test/presubmit_test.go

 package test
 
+// These tests check for meta level items, like trailing whitespace, correct file naming etc.
+
 import (
 	"bufio"
 	"fmt"
@@ -30,7 +32,6 @@ func hasTrailingWhitespace(path string, info os.FileInfo, _ error) error {
 		return nil
 	}
 
-	println("looking at", path)
 	file, err := os.Open(path)
 	if err != nil {
 		return nil
@@ -48,3 +49,29 @@ func hasTrailingWhitespace(path string, info os.FileInfo, _ error) error {
 
 	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
+}