Move names regular expressions to api/v2 packages

Because the repository name definitions are part of the v2 specification, they
have been moved out of the common package. This is part of the effort to break
up the common package into more sensible components.

Signed-off-by: Stephen J Day <stephen.day@docker.com>

api/v2/names_test.go

@@ -0,0 +1,91 @@
+package v2
+
+import (
+	"testing"
+)
+
+func TestRepositoryNameRegexp(t *testing.T) {
+	for _, testcase := range []struct {
+		input string
+		err   error
+	}{
+		{
+			input: "simple/name",
+		},
+		{
+			input: "library/ubuntu",
+		},
+		{
+			input: "docker/stevvooe/app",
+		},
+		{
+			input: "aa/aa/aa/aa/aa/aa/aa/aa/aa/bb/bb/bb/bb/bb/bb",
+			err:   ErrRepositoryNameTooManyComponents,
+		},
+		{
+			input: "aa/aa/bb/bb/bb",
+		},
+		{
+			input: "a/a/a/b/b",
+			err:   ErrRepositoryNameComponentShort,
+		},
+		{
+			input: "a/a/a/a/",
+			err:   ErrRepositoryNameComponentShort,
+		},
+		{
+			input: "foo.com/bar/baz",
+		},
+		{
+			input: "blog.foo.com/bar/baz",
+		},
+		{
+			input: "asdf",
+			err:   ErrRepositoryNameMissingComponents,
+		},
+		{
+			input: "asdf$$^/aa",
+			err:   ErrRepositoryNameComponentInvalid,
+		},
+		{
+			input: "aa-a/aa",
+		},
+		{
+			input: "aa/aa",
+		},
+		{
+			input: "a-a/a-a",
+		},
+		{
+			input: "a",
+			err:   ErrRepositoryNameMissingComponents,
+		},
+		{
+			input: "a-/a/a/a",
+			err:   ErrRepositoryNameComponentInvalid,
+		},
+	} {
+
+		failf := func(format string, v ...interface{}) {
+			t.Logf(testcase.input+": "+format, v...)
+			t.Fail()
+		}
+
+		if err := ValidateRespositoryName(testcase.input); err != testcase.err {
+			if testcase.err != nil {
+				if err != nil {
+					failf("unexpected error for invalid repository: got %v, expected %v", err, testcase.err)
+				} else {
+					failf("expected invalid repository: %v", testcase.err)
+				}
+			} else {
+				if err != nil {
+					// Wrong error returned.
+					failf("unexpected error validating repository name: %v, expected %v", err, testcase.err)
+				} else {
+					failf("unexpected error validating repository name: %v", err)
+				}
+			}
+		}
+	}
+}