Re: Proposal for Assert.assertException

"David Saff [email protected] [junit]" <[email protected]> Tue, 19 May 2015 13:57:40 -0400
Newsgroups gmane.comp.java.junit.user
Message-ID <CALrw-PxjsEdUvjZHFZcPRFYedAjxi9B8OZoTMPH4HMKO=OU29Q@mail.gmail.com>
--001a113ee5e21bbfec0516730de4
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

Quite useful.

At this point, we haven't started adding JUnit 8-focused features, but I
believe we plan to soon.  Does that sound right, Marc?

Thanks,

   David

On Tue, May 19, 2015 at 1:06 AM, Johannes [email protected] [junit] <
[email protected]> wrote:

>
>
> Hello,
>
> I always found testing thrown exceptions tedious, since it required a
> new test method for every exception that shall be thrown.
> Since the introduction of Java 8 lambda expressions I found this new
> idiom to be quite useful:
>
> @Test
> public void testIndexOutOfBoundsIsThrown() {
> List<Object> l =3D new ArrayList<>();
> assertException(() -> l.add(-1, new Object()));
> assertException(() -> l.add(1, new Object()),
> IndexOutOfBoundsException.class);
> }
>
> Here is the code for the assertions:
>
> public static void assertException(Runnable r) {
> assertException(r, Exception.class);
> }
>
> public static void assertException(Runnable r, Class<? extends
> Exception> exceptionClass) {
> try {
> r.run();
> fail("expected " + exceptionClass.getName());
> } catch (Exception e) {
> Assert.assertTrue("expected " + exceptionClass + " but was
> " + e,
> exceptionClass.isAssignableFrom(e.getClass()));
> }
> }
>
> What do you think?
> If you like the idea, I can create a pull request on github.
>
> Johannes
>=20=20
>

--001a113ee5e21bbfec0516730de4
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable





<head>

<style type=3D"text/css">
<!--

/* start of attachment style */
       .ygrp-photo-title{
         clear: both;
         font-size: smaller;
         height: 15px;
         overflow: hidden;
         text-align: center;
         width: 75px;
       }
       div.ygrp-photo{
         background-position: center;
         background-repeat: no-repeat;
         background-color: white;
         border: 1px solid black;
         height: 62px;
         width: 62px;
       }

       div.photo-title=20
         a,
         div.photo-title a:active,
         div.photo-title a:hover,
         div.photo-title a:visited {
           text-decoration: none;=20
       }

       div.attach-table div.attach-row {
         clear: both;
       }

       div.attach-table div.attach-row div {
         float: left;
         /* margin: 2px;*/
       }

       p {
         clear: both;
         padding: 15px 0 3px 0;
	 overflow: hidden;
       }

       div.ygrp-file {
         width: 30px;
         valign: middle;
       }
       div.attach-table div.attach-row div div a {
         text-decoration: none;
       }

       div.attach-table div.attach-row div div span {
         font-weight: normal;
       }

       div.ygrp-file-title {
         font-weight: bold;
       }
 /* end of attachment style */
        -->
        </style>
        </head>
<html>
<head>
<style type=3D"text/css">
<!--
#ygrp-mkp {
  border: 1px solid #d8d8d8;
  font-family: Arial;
  margin: 10px 0;
  padding: 0 10px;
}

#ygrp-mkp hr {
  border: 1px solid #d8d8d8;
}

#ygrp-mkp #hd {
  color: #628c2a;
  font-size: 85%;
  font-weight: 700;
  line-height: 122%;
  margin: 10px 0;
}

#ygrp-mkp #ads {
  margin-bottom: 10px;
}

#ygrp-mkp .ad {
  padding: 0 0;
}

#ygrp-mkp .ad p {
  margin: 0;
}

#ygrp-mkp .ad a {
  color: #0000ff;
  text-decoration: none;
}
-->
</style>
</head>
<body>



<!-- |**|begin egp html banner|**| -->

<br><br>

<!-- |**|end egp html banner|**| -->


<div dir=3D"ltr">Quite useful.<div><br></div><div>At this point, we haven&#=
39;t started adding JUnit 8-focused features, but I believe we plan to soon=
.=C2=A0 Does that sound right, Marc?</div><div><br></div><div>Thanks,</div>=
<div><br></div><div>=C2=A0 =C2=A0David</div></div><div class=3D"gmail_extra=
"><br><div class=3D"gmail_quote">On Tue, May 19, 2015 at 1:06 AM, Johannes =
<a href=3D"mailto:[email protected]">[email protected]</a> [jun=
it] <span dir=3D"ltr">&lt;<a href=3D"mailto:[email protected]" target=
=3D"_blank">[email protected]</a>&gt;</span> wrote:<br><blockquote clas=
s=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;pad=
ding-left:1ex">


<u></u>









=20
<div style=3D"background-color:#fff">
<span>=C2=A0</span>


<div>
  <div>


    <div>
=20=20=20=20=20=20
=20=20=20=20=20=20
      <p>Hello,<br>
<br>
I always found testing thrown exceptions tedious, since it required a <br>
new test method for every exception that shall be thrown.<br>
Since the introduction of Java 8 lambda expressions I found this new <br>
idiom to be quite useful:<br>
<br>
@Test<br>
     public void testIndexOutOfBoundsIsThrown() {<br>
         List&lt;Object&gt; l =3D new ArrayList&lt;&gt;();<br>
         assertException(() -&gt; l.add(-1, new Object()));<br>
         assertException(() -&gt; l.add(1, new Object()), <br>
IndexOutOfBoundsException.class);<br>
     }<br>
<br>
Here is the code for the assertions:<br>
<br>
public static void assertException(Runnable r) {<br>
         assertException(r, Exception.class);<br>
     }<br>
<br>
public static void assertException(Runnable r, Class&lt;? extends <br>
Exception&gt; exceptionClass) {<br>
         try {<br>
             r.run();<br>
             fail(&quot;expected &quot; + exceptionClass.getName());<br>
         } catch (Exception e) {<br>
             Assert.assertTrue(&quot;expected &quot; + exceptionClass + &qu=
ot; but was <br>
&quot; + e,<br>
                     exceptionClass.isAssignableFrom(e.getClass()));<br>
         }<br>
     }<br>
<br>
What do you think?<br>
If you like the idea, I can create a pull request on github.<br>
<br>
Johannes<br>
</p>

    </div>
=20=20=20=20=20

=20=20=20=20
    <div style=3D"color:#fff;min-height:0"></div>


</div>



=20=20






</blockquote></div><br></div>




<!-- |**|begin egp html banner|**| -->

<br>


<br>

<!-- |**|end egp html banner|**| -->


<div width=3D"1" style=3D"color: white; clear: both;"/>__._,_.___</div>

=20=20=20=20=20=20
=20=20

=20=20=20=20
    <div id=3D"fromDMARC" style=3D"clear:both; margin-top: 10px;">
         <hr style=3D"height:2px ; border-width:0; color:#E3E3E3; backgroun=
d-color:#E3E3E3;">
         Posted by: David Saff &lt;[email protected]&gt;         <hr style=3D=
"height:2px ; border-width:0; color:#E3E3E3; background-color:#E3E3E3;">
    </div>
<!-- Start Recommendations -->
<!-- End Recommendations -->



<!-- |**|begin egp html banner|**| -->

  <img src=3D"http://geo.yahoo.com/serv?s=3D97476590/grpId=3D2423328/grpspI=
d=3D1705006905/msgId=3D24659/stime=3D1432058282" width=3D"1" height=3D"1"> =
<br>

<!-- |**|end egp html banner|**| -->

=20=20
<!-- |**|begin egp html banner|**| -->

<br>



=20=20=20
=20=20=20=20=20
=20
        <!-- |**|begin egp html banner|**| -->
        <div id=3D"ygrp-vital" style=3D"background-color: #f2f2f2; font-fam=
ily: Verdana; font-size: 10px; margin-bottom: 10px; padding: 10px;">

        <span id=3D"vithd" style=3D"font-weight: bold; color: #333; text-tr=
ansform: uppercase; "><a href=3D"https://groups.yahoo.com/neo/groups/junit/=
info;_ylc=3DX3oDMTJldmU1NGtnBF9TAzk3MzU5NzE0BGdycElkAzI0MjMzMjgEZ3Jwc3BJZAM=
xNzA1MDA2OTA1BHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTQzMjA1ODI4Mg--" style=3D"tex=
t-decoration: none;">Visit Your Group</a></span>

     <ul style=3D"list-style-type: none; margin: 0; padding: 0; display: in=
line;">
            <li style=3D"border-right: 1px solid #000; font-weight: 700; di=
splay: inline; padding: 0 5px; margin-left: 0;">
      <span class=3D"cat"><a href=3D"https://groups.yahoo.com/neo/groups/ju=
nit/members/all;_ylc=3DX3oDMTJmNmt2OXVoBF9TAzk3MzU5NzE0BGdycElkAzI0MjMzMjgE=
Z3Jwc3BJZAMxNzA1MDA2OTA1BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzE0MzIwNTgyODI-" s=
tyle=3D"text-decoration: none;">New Members</a></span>
      <span class=3D"ct" style=3D"color: #ff7900;">4</span>
    </li>
                                              </ul>
  </div>


<div id=3D"ft" style=3D"font-family: Arial; font-size: 11px; margin-top: 5p=
x; padding: 0 2px 0 0; clear: both;">
  <a href=3D"https://groups.yahoo.com/neo;_ylc=3DX3oDMTJkODFjbDg1BF9TAzk3ND=
c2NTkwBGdycElkAzI0MjMzMjgEZ3Jwc3BJZAMxNzA1MDA2OTA1BHNlYwNmdHIEc2xrA2dmcARzd=
GltZQMxNDMyMDU4Mjgy" style=3D"float: left;"><img src=3D"http://l.yimg.com/r=
u/static/images/yg/img/email/new_logo/logo-groups-137x15.png" height=3D"15"=
 width=3D"137" alt=3D"Yahoo! Groups" style=3D"border: 0;"/></a>
  <div style=3D"color: #747575; float: right;"> &bull; <a href=3D"https://i=
nfo.yahoo.com/privacy/us/yahoo/groups/details.html" style=3D"text-decoratio=
n: none;">Privacy</a> &bull; <a href=3D"mailto:junit-unsubscribe@yahoogroup=
s.com?subject=3DUnsubscribe" style=3D"text-decoration: none;">Unsubscribe</=
a> &bull; <a href=3D"https://info.yahoo.com/legal/us/yahoo/utos/terms/" sty=
le=3D"text-decoration: none;">Terms of Use</a> </div>
</div>

<!-- |**|end egp html banner|**| -->

  </div> <!-- ygrp-msg -->

=20=20=20


  <br>

<!-- |**|end egp html banner|**| -->


<div style=3D"color: white; clear: both;"/>__,_._,___</div>
</body>

</html>

--001a113ee5e21bbfec0516730de4--