doc: edit writing-tests.md

[Trott]

• Remove passive voice
• Remove unneeded modifiers
• Minor comma change

Checklist

• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

doc test

[gibfahn]

Why the passive->active change here? Is this a general rule we follow? I find if there are variables leaked into the global space less clear than if variables are leaked into the global space.

[Trott]

How about if the test leaks variables into the global space?

The passive->active change is just following a general writing recommendation for increased clarity, but of course we should stick to passive voice if changing to active does not increase clarity. :-D

[gibfahn]

LGTM with nit

[gibfahn]

4-seconds->4-second

[thefourtheye]

"include the common module, as the first executable statement" maybe?

[gibfahn]

Or maybe to be really clear just say that the first two lines of the test must be:

'use strict';
const common = require('../common');

or

'use strict';
require('../common');

[thefourtheye]

Generally, this holds good. But in some tests we have comments at the beginning (I mean before common) and that is also acceptable.

[gibfahn]

Is there a reason we couldn't just standardise on what's in this guide?

'use strict';
require('../common');

// Comments after this

[gibfahn]

If we did that we could lint for it.

[thefourtheye]

Lets see what @Trott thinks about it.

[Trott]

How about include the common module before any other modules. as a reasonable concise compromise that we can expand on later if it is found to be inadequate?

[jasnell]

Ping @Trott

[Trott]

Nits addressed, I think.

[Trott]

Landed in 0674789