Cd builtin

[Mte90]

Following the new contributing guide I was able to add the cd builtin :-)

I updated the guide a bit to be more clear.

Ref: #215

[Mte90]

So in the ticket we are talking about making this builtin as failable but to be shellcheck validated we need to support the case that fails || exit.

How we can handle that behavior?

[Ph0enixKM]

Wow! Good job @Mte90! I appreciate that modifications to the contributor guide 👏👏. Now if you want to make this failable, you have to add these 3 lines of code. Can you also add some information about it to the contributing guide?

[Mte90]

So now is failable but the test fails Failed expression must be followed by a block or statement.

I can't use unsafe before cd.

[MuhamedMagdi]

I think we need also to add the cd keyword to the reserved keywords list in src/modules/variable/mod.rs
Ref: #318

[Mte90]

good catch @MuhamedMagdi I updated in this PR the contributing guide.

[Ph0enixKM]

@Mte90 Can this PR stall until I change the API for TranslateModule? I'm talking about the solution that I proposed here: https://www.youtube.com/watch?v=_caXIMxrYj8

[Ph0enixKM]

I'd say that this issue is stalled until this one is finished: #183

I'll do that one first so that we can move forward

[Mte90]

Sure the other one is more important

[b1ek]

@Ph0enixKM please review again

[KrosFire]

LGTM

[Ph0enixKM]

I just realized that you should also use Command Modifier to give ability to use the unsafe (soon it will be assume) keyword here.

To parse the command modifier, you need to parse the command and self.failed in the command modifier context. Here is how it's done. You don't translate the command modifiers since they don't need to be translated.

Remember to use CommandModifier::new().parse_expr() instead of just CommandModifier::new() as the function will not make it look for expression (this should be simplified to CommandModifier::new() though. I'll fix it once you update this PR)

[Ph0enixKM]

Okay @Mte90 let's remove the self.failed

[Ph0enixKM]

LGTM

obsolete