oauth2, jws, internal: more style fixes for bad test messages

Change-Id: Id2805fd77fb11d975414eb66689efab284a18805
Reviewed-on: https://go-review.googlesource.com/27911
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/internal/token_test.go b/internal/token_test.go
index d8d1e98..5ed0b15 100644
--- a/internal/token_test.go
+++ b/internal/token_test.go
@@ -14,23 +14,22 @@
 	RegisterBrokenAuthHeaderProvider("https://aaa.com/")
 	tokenURL := "https://aaa.com/token"
 	if providerAuthHeaderWorks(tokenURL) {
-		t.Errorf("URL: %s is a broken provider", tokenURL)
+		t.Errorf("got %q as unbroken; want broken", tokenURL)
 	}
 }
 
 func Test_providerAuthHeaderWorks(t *testing.T) {
 	for _, p := range brokenAuthHeaderProviders {
 		if providerAuthHeaderWorks(p) {
-			t.Errorf("URL: %s not found in list", p)
+			t.Errorf("got %q as unbroken; want broken", p)
 		}
 		p := fmt.Sprintf("%ssomesuffix", p)
 		if providerAuthHeaderWorks(p) {
-			t.Errorf("URL: %s not found in list", p)
+			t.Errorf("got %q as unbroken; want broken", p)
 		}
 	}
 	p := "https://api.not-in-the-list-example.com/"
 	if !providerAuthHeaderWorks(p) {
-		t.Errorf("URL: %s found in list", p)
+		t.Errorf("got %q as unbroken; want broken", p)
 	}
-
 }
diff --git a/jws/jws_test.go b/jws/jws_test.go
index 9b5efdd..39a136a 100644
--- a/jws/jws_test.go
+++ b/jws/jws_test.go
@@ -41,6 +41,6 @@
 func TestVerifyFailsOnMalformedClaim(t *testing.T) {
 	err := Verify("abc.def", nil)
 	if err == nil {
-		t.Error("Improperly formed JWT should fail.")
+		t.Error("got no errors; want improperly formed JWT not to be verified")
 	}
 }
diff --git a/transport_test.go b/transport_test.go
index 9bb1383..d6e8087 100644
--- a/transport_test.go
+++ b/transport_test.go
@@ -18,12 +18,12 @@
 	server := newMockServer(func(w http.ResponseWriter, r *http.Request) {})
 	defer server.Close()
 	client := &http.Client{Transport: tr}
-	res, err := client.Get(server.URL)
+	resp, err := client.Get(server.URL)
 	if err == nil {
-		t.Errorf("a nil Source was passed into the transport expected an error")
+		t.Errorf("got no errors, want an error with nil token source")
 	}
-	if res != nil {
-		t.Errorf("expected a nil response, got %v", res)
+	if resp != nil {
+		t.Errorf("Response = %v; want nil", resp)
 	}
 }
 
@@ -37,8 +37,8 @@
 		Source: ts,
 	}
 	server := newMockServer(func(w http.ResponseWriter, r *http.Request) {
-		if r.Header.Get("Authorization") != "Bearer abc" {
-			t.Errorf("Transport doesn't set the Authorization header from the fetched token")
+		if got, want := r.Header.Get("Authorization"), "Bearer abc"; got != want {
+			t.Errorf("Authorization header = %q; want %q", got, want)
 		}
 	})
 	defer server.Close()
@@ -90,7 +90,7 @@
 func TestTokenValidNoAccessToken(t *testing.T) {
 	token := &Token{}
 	if token.Valid() {
-		t.Errorf("Token should not be valid with no access token")
+		t.Errorf("got valid with no access token; want invalid")
 	}
 }
 
@@ -99,7 +99,7 @@
 		Expiry: time.Now().Add(-5 * time.Hour),
 	}
 	if token.Valid() {
-		t.Errorf("Token should not be valid if it expired in the past")
+		t.Errorf("got valid with expired token; want invalid")
 	}
 }