# Unit testing generated content

**URL:** <https://www.ruby-forum.com/t/unit-testing-generated-content/173925>\
**Category:** Ruby\
**Created:** [August 18, 2009, 10:35am UTC](https://www.ruby-forum.com/t/unit-testing-generated-content/173925 "2009-08-18T10:35:06Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [August 18, 2009, 10:35am UTC](https://www.ruby-forum.com/t/unit-testing-generated-content/173925/1 "2009-08-18T10:35:06Z")

</div>

Hi,

I’m writing unit test.

I’ve programmed already an assert method, which purpose it to compare  
a string or a file with unix diff.  
The goal is to assert that a generated content multiline is exactly  
what I expect.

All the beginning of the code is a kind of polymorphism, treating  
argument as string or filename

All the assert job is really done in the 4 last line, with unix diff.

```
def assert_content_equal(expected, actual, message = nil)
    # compare avec diff
    expected_f = "/tmp/expected#{$$}"
    actual_f = "/tmp/actual#{$$}"
    remove_expected_f = true
    remove_actual_f = true

    if expected.kind_of? String
        if (expected.size < 255 and FileTest.exists? expected)
            expected_f = expected
            remove_expected_f = false
        else
            # création du fichier avec le contenu de la string

```

expected  
File.open(expected\_f, “w”) { |f| f.print expected }  
end  
else  
raise “expected String ou nom de fichier”  
end

```
    # code idem avec s/expected/actual/g
    # besoin de matchit : ?if expected^MV%%"cy/# code idem^M2jV%

```

%x"cPV%%:s/expected/actual/g^M  
if actual.kind\_of? String  
if (actual.size \< 255 and FileTest.exists? actual)  
actual\_f = actual  
remove\_actual\_f = false  
else  
# création du fichier avec le contenu de la string  
actual  
File.open(actual\_f, “w”) { |f| f.print actual }  
end  
else  
raise “actual String ou nom de fichier”  
end

```
    diff = `diff #{expected_f} #{actual_f}`
    File.unlink(expected_f) if remove_expected_f
    File.unlink(actual_f) if remove_actual_f
    assert_block("échec diff <expected >actual\n#{diff}") { $? ==

```

0 }  
end

What I would like to do now, is to have a regexp assert multiline  
match, some thing like :

assert\_match\_regexp(actual) {  
/^start/  
/something ._/  
/^\s_$/  
/^end/  
}

Which mean I expect 4 lines, individually matching the associated  
regexp

Do you see a want to achieve?

I mean, reading the blockgiven, counting the regexp, and asserting the  
whole…

More that that a full regexpdiff in fact ! 😉

Any link or clue/hint, would be nice.

Regards,  
Sylvain.

---

<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [August 18, 2009, 12:22pm UTC](https://www.ruby-forum.com/t/unit-testing-generated-content/173925/2 "2009-08-18T12:22:39Z")

</div>

sylvain wrote:

> What I would like to do now, is to have a regexp assert multiline  
> match, some thing like :
> 
> assert\_match\_regexp(actual) {  
> /^start/  
> /something ._/  
> /^\s_$/  
> /^end/  
> }
> 
> Which mean I expect 4 lines, individually matching the associated  
> regexp

You can match a single regexp across a multi-line string; using /m  
option is clearer since . then matches any character including newline.

> > str = “foo\nbar\nbaz\nbap\n”  
> > =\> “foo\nbar\nbaz\nbap\n”
> 
> > str =~ /^bar$\n^baz$\n^bap$/m  
> > =\> 4
> 
> > str =~ /^bar$.\*^bap$/m  
> > =\> 4

---

<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [August 18, 2009, 12:50pm UTC](https://www.ruby-forum.com/t/unit-testing-generated-content/173925/3 "2009-08-18T12:50:43Z")

</div>

sylvain wrote:

> What I would like to do now, is to have a regexp assert multiline  
> match, some thing like :
> 
> assert\_match\_regexp(actual) {  
> /^start/  
> /something ._/  
> /^\s_$/  
> /^end/  
> }
> 
> Which mean I expect 4 lines, individually matching the associated  
> regexp
> 
> Do you see a want to achieve?
> 
> I mean, reading the blockgiven, counting the regexp, and asserting the  
> whole…
> 
> More that that a full regexpdiff in fact ! 😉
> 
> Any link or clue/hint, would be nice.

How about:

def test\_it(str)  
num\_lines = 4  
regexs = [/^start/, /something ._/, /^\s_$/, /^end/]

lines = str.split("\n")  
return false if lines.length != num\_lines

match\_results = lines.zip(regexs).collect{|line, regex| line =~ regex}  
match\_results.all?  
end

s1 =\<\<ENDOFSTRING  
start  
something else

end of data  
ENDOFSTRING

s2 =\<\<ENDOFSTRING  
start  
something else

end of data  
too many lines  
ENDOFSTRING

s3 =\<\<ENDOFSTRING  
start  
something else  
no match here  
end of data  
ENDOFSTRING

[s1, s2, s3].each do |str|  
puts test\_it(str)  
end

–output:–  
true  
false  
false

---

<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [August 18, 2009, 5:20pm UTC](https://www.ruby-forum.com/t/unit-testing-generated-content/173925/4 "2009-08-18T17:20:13Z")

</div>

Hi,

Hey cool seems great.  
I’ve tried to find a way of passing regexps through the block (Proc)  
without  
success.

But by array it’s fine too.

def test\_it(str)

> num\_lines = 4  
> regexs = [/^start/, /something ._/, /^\s_$/, /^end/]
> 
> lines = str.split("\n")  
> return false if lines.length != num\_lines
> 
> match\_results = lines.zip(regexs).collect{|line, regex| line =~ regex}  
> match\_results.all?  
> end

Thanks, I will post the final assert, when It will be ready.

Do you think I can group my own assertion in a module or something and  
load  
it into my testcase ?  
For the moment I’ve just added a method into the testcase, was used only  
here.

Regards,  
Sylvain Viart.