fix(v2/tests): make comments and tests agree about what's being tested

In cases where the comments were incorrect, this changes them to agree
with the tests.  In cases where the comments were correct, this extends
the tests to cover the behavior described in the comment.

server/v2/tests/delete_handler_test.go

@@ -31,7 +31,7 @@ func TestV2DeleteKey(t *testing.T) {
 // Ensures that an empty directory is deleted when dir is set.
 //
 //   $ curl -X PUT localhost:4001/v2/keys/foo?dir=true
-//   $ curl -X PUT localhost:4001/v2/keys/foo ->fail
+//   $ curl -X DELETE localhost:4001/v2/keys/foo ->fail
 //   $ curl -X DELETE localhost:4001/v2/keys/foo?dir=true
 //
 func TestV2DeleteEmptyDirectory(t *testing.T) {

server/v2/tests/put_handler_test.go

@@ -77,7 +77,7 @@ func TestV2SetKeyWithBadTTL(t *testing.T) {
 	})
 }
 
-// Ensures that a key is conditionally set only if it previously did not exist.
+// Ensures that a key is conditionally set if it previously did not exist.
 //
 //   $ curl -X PUT localhost:4001/v2/keys/foo/bar -d value=XXX -d prevExist=false
 //
@@ -93,10 +93,10 @@ func TestV2CreateKeySuccess(t *testing.T) {
 	})
 }
 
-// Ensures that a key is not conditionally because it previously existed.
+// Ensures that a key is not conditionally set because it previously existed.
 //
-//   $ curl -X PUT localhost:4001/v2/keys/foo/bar -d value=XXX
 //   $ curl -X PUT localhost:4001/v2/keys/foo/bar -d value=XXX -d prevExist=false
+//   $ curl -X PUT localhost:4001/v2/keys/foo/bar -d value=XXX -d prevExist=false -> fail
 //
 func TestV2CreateKeyFail(t *testing.T) {
 	tests.RunServer(func(s *server.Server) {
@@ -158,19 +158,25 @@ func TestV2UpdateKeyFailOnValue(t *testing.T) {
 
 // Ensures that a key is not conditionally set if it previously did not exist.
 //
-//   $ curl -X PUT localhost:4001/v2/keys/foo -d value=XXX -d prevExist=true
-//   $ curl -X PUT localhost:4001/v2/keys/foo/bar -d value=XXX -d prevExist=true
+//   $ curl -X PUT localhost:4001/v2/keys/foo -d value=YYY -d prevExist=true -> fail
+//   $ curl -X PUT localhost:4001/v2/keys/foo/bar -d value=YYY -d prevExist=true -> fail
 //
 func TestV2UpdateKeyFailOnMissingDirectory(t *testing.T) {
 	tests.RunServer(func(s *server.Server) {
 		v := url.Values{}
 		v.Set("value", "YYY")
 		v.Set("prevExist", "true")
-		resp, _ := tests.PutForm(fmt.Sprintf("%s%s", s.URL(), "/v2/keys/foo/bar"), v)
+		resp, _ := tests.PutForm(fmt.Sprintf("%s%s", s.URL(), "/v2/keys/foo"), v)
 		body := tests.ReadBodyJSON(resp)
 		assert.Equal(t, body["errorCode"], 100, "")
 		assert.Equal(t, body["message"], "Key not found", "")
 		assert.Equal(t, body["cause"], "/foo", "")
+
+		resp, _ = tests.PutForm(fmt.Sprintf("%s%s", s.URL(), "/v2/keys/foo/bar"), v)
+		body = tests.ReadBodyJSON(resp)
+		assert.Equal(t, body["errorCode"], 100, "")
+		assert.Equal(t, body["message"], "Key not found", "")
+		assert.Equal(t, body["cause"], "/foo", "")
 	})
 }