Comments on: Flaw: Digging into Collaborators

By: Luke

Luke — Wed, 01 Dec 2010 00:02:29 +0000

I wouldn’t worry about objects passed in but not used directly (well, depending on the use case). Take a look at your first concrete example. The Law of Demeter says use no more than one “dot,” so for example:

Instead of:

public Connection getDbConnection(String dbName, String dbPort, String username, String password) {
return myDb.createConnection(
dbName,
dbPort,
username,
password);
}

This would be preferred:

public Connection getDbConnection(ConnectionInfo connInfo) {
return myDb.createConnection(
connInfo.getDbName(),
connInfo.getDbPort(),
connInfo.getUsername(),
connInfo.getPassword());
}

And in this (fictional) example, creating a ConnectionInfo object during testing is trivial because the ConnectionInfo class is just a bag of properties (model object).

If, later, I need another property, I only have to modify ConnectionInfo and not my method declaration.

By: Linking to Mi?ko’s, Russ’ and my Testability Guide at JAW Speak

Linking to Mi?ko’s, Russ’ and my Testability Guide at JAW Speak — Tue, 08 Jun 2010 04:59:25 +0000

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Thu, 25 Mar 2010 17:50:23 +0000

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By: Niceboomer and the future of changes » Blog Archive » Guide: Writing Testable Code

Fri, 12 Feb 2010 20:51:46 +0000

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By: Einführung in TDD & Clean Code Talks | geekcloud.org

Einführung in TDD & Clean Code Talks | geekcloud.org — Sun, 22 Nov 2009 14:50:55 +0000

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By: Rafael Naufal

Rafael Naufal — Fri, 23 Jan 2009 16:00:06 +0000

Great post, Misko. It helps a lot improving the code design by showing the problems of not passing explicitly the objects to methods or constructors. Just one remark: In the “Problem: Law of Demeter Violated to Inappropriately make a Service Locator” section, there’s no assignment to the Lock member variable at the UpdateBug constructor.

By: Guide to Writing Testable Code / CODEISPOETRY

Guide to Writing Testable Code / CODEISPOETRY — Thu, 11 Dec 2008 01:38:01 +0000

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By: Vlad

Vlad — Fri, 28 Nov 2008 10:02:36 +0000

Hi!
I enjoy your posts and I’ve been inspired to add more test to my code.

My question is if it is a flaw or not if one method has an argument that is both used directly and also to access some sub-object.

For example in the LoginPage, if login() needs both the client and the authenticator, is it okay to just send the client as a parameter, or should one send both client and authenticator?

best regards,
Vlad

By: Guide to Writing Testable Code | Miško Hevery

Guide to Writing Testable Code | Miško Hevery — Wed, 26 Nov 2008 18:04:00 +0000

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