Building expressions

Ruby IronRuby
1

Hi

I’m trying to get some Moq mockery going in IronRuby but Moq expects
Expression<Func<MyObject, TReturn>> in his methods.
Is there a way to make a RubyProc/lambda return an expression or convert
it
to an expression?

Met vriendelijke groeten - Best regards - Salutations
Ivan Porto C.
Author of IronRuby in Action (http://manning.com/carrero)

Steve M.
http://www.brainyquote.com/quotes/authors/s/steve_martin.html

  • “I’ve got to keep breathing. It’ll be my worst business mistake if I
    don’t.”
2

It cannot be done. Even if you could get to the ExpressionTree of a Ruby
lambda, the ExpressionTree would be loosely-bound as Ruby uses
duck-typing, whereas Moq expects a strongly-typed ExpressionTree so that
it can figure out the exact method that you are trying to associate some
expectation with.

FWIW, Mark had also been playing with mocking, and in our discussions,
we said that the easiest mocking approach would be to use Ruby features
like method_missing, monkey-patching, etc (like rspec does). Ie.
something like this:

def mock(clrInterface):
class ClrMock < clrInterface
# monkey-patch all of “clrInterface.methods" here, and redirect to
the mocking framework
end
return ClrMock.new
end

From: [email protected]
[mailto:[email protected]] On Behalf Of Ivan Porto
Carrero
Sent: Sunday, May 03, 2009 3:18 AM
To: ironruby-core
Subject: [Ironruby-core] Building expressions

Hi

I’m trying to get some Moq mockery going in IronRuby but Moq expects
Expression<Func<MyObject, TReturn>> in his methods.
Is there a way to make a RubyProc/lambda return an expression or convert
it to an expression?

Met vriendelijke groeten - Best regards - Salutations
Ivan Porto C.
Author of IronRuby in Action (http://manning.com/carrero)

Steve
Martinhttp://www.brainyquote.com/quotes/authors/s/steve_martin.html -
“I’ve got to keep breathing. It’ll be my worst business mistake if I
don’t.”

3

Ivan,

You may want to try Jeremy Mcanally’s
stumphttp://github.com/jeremymcanally/stump/tree/mastermocking
framework. I haven’t used it much, so I can’t give any additional
info on it. It may not be what you are wanting, but if you just need
mocks,
it may be worth a shot.

Ryan R.
[email protected]
http://panesofglass.org/
http://wizardsofsmart.net/

4

Yes
I have since changed my approach. I’ve also talked with Mark about
approaching this.

The approach I take now is to generate a proxy to the
object/class/interface
that will record method calls.
After recording you can then run verifications on those method calls.
The
way I generate the proxy for an interface came out of my talk with Mark.

But the deeper implication is then that when a library uses
Expression<Func<,>> as parameters you cannot use it from ironruby at
all?
Not even by building the expression tree yourself?

(I forgot to hit send apparently :))

Met vriendelijke groeten - Best regards - Salutations
Ivan Porto C.
GSM: +32.486.787.582
Blog: http://flanders.co.nz
Twitter: http://twitter.com/casualjim
Author of IronRuby in Action (http://manning.com/carrero)

Emo Philips
http://www.brainyquote.com/quotes/authors/e/emo_philips.html

  • “I got some new underwear the other day. Well, new to me.”
5

Of course you should be able to build the expression tree manually –
though even here, you may have trouble under .NET 3.5 as a result of the
duplicated namespace. (That issue goes away with .NET 4.)

From: [email protected]
[mailto:[email protected]] On Behalf Of Ivan Porto
Carrero
Sent: Tuesday, May 05, 2009 7:46 AM
To: [email protected]
Subject: Re: [Ironruby-core] Building expressions

Yes
I have since changed my approach. I’ve also talked with Mark about
approaching this.

The approach I take now is to generate a proxy to the
object/class/interface that will record method calls.
After recording you can then run verifications on those method calls.
The way I generate the proxy for an interface came out of my talk with
Mark.

But the deeper implication is then that when a library uses
Expression<Func<,>> as parameters you cannot use it from ironruby at
all? Not even by building the expression tree yourself?

(I forgot to hit send apparently :))

Met vriendelijke groeten - Best regards - Salutations
Ivan Porto C.
GSM: +32.486.787.582
Blog: http://flanders.co.nz
Twitter: http://twitter.com/casualjim
Author of IronRuby in Action (http://manning.com/carrero)

Emo
Philipshttp://www.brainyquote.com/quotes/authors/e/emo_philips.html -
“I got some new underwear the other day. Well, new to me.”
On Sun, May 3, 2009 at 11:37 PM, Shri B.
<[email protected]mailto:[email protected]> wrote:

It cannot be done. Even if you could get to the ExpressionTree of a Ruby
lambda, the ExpressionTree would be loosely-bound as Ruby uses
duck-typing, whereas Moq expects a strongly-typed ExpressionTree so that
it can figure out the exact method that you are trying to associate some
expectation with.

FWIW, Mark had also been playing with mocking, and in our discussions,
we said that the easiest mocking approach would be to use Ruby features
like method_missing, monkey-patching, etc (like rspec does). Ie.
something like this:

def mock(clrInterface):

class ClrMock < clrInterface

# monkey-patch all of “clrInterface.methods" here, and redirect to

the mocking framework

end

return ClrMock.new

end

From:
[email protected]mailto:[email protected]
[mailto:[email protected]mailto:[email protected]]
On Behalf Of Ivan Porto C.
Sent: Sunday, May 03, 2009 3:18 AM
To: ironruby-core
Subject: [Ironruby-core] Building expressions

Hi

I’m trying to get some Moq mockery going in IronRuby but Moq expects
Expression<Func<MyObject, TReturn>> in his methods.
Is there a way to make a RubyProc/lambda return an expression or convert
it to an expression?

Met vriendelijke groeten - Best regards - Salutations
Ivan Porto C.
Author of IronRuby in Action (http://manning.com/carrero)

Steve
Martinhttp://www.brainyquote.com/quotes/authors/s/steve_martin.html -
“I’ve got to keep breathing. It’ll be my worst business mistake if I
don’t.”

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