Render alert fields when performing searches

[LawnGnome]

We have all this useful information in the web UI that comes back from GraphQL, but isn't exposed in src. This PR wires up a common renderer to the actions exec and search commands to render any alert that comes back in a (hopefully) human readable form.

Here are a couple of examples of it in use:

If we think this is useful, I'll add a couple of tests to the alert rendering and we can get this merged.

[sqs]

Definitely useful!

[eseliger]

Very cool!

[LawnGnome]

OK, this is ready for review.

[sqs]

This would have helped reduce confusion with an issue facing a customer right now: https://sourcegraph.slack.com/archives/CJX299FGE/p1592345898255500.

[mrnugget]

Code looks good to me! 👍

Visually, though, I think this might be a bit hard to parse, since we have up to 4 colors:

[LawnGnome]

Visually, though, I think this might be a bit hard to parse, since we have up to 4 colors:

Yeah, I'm not going to say the colours were picked totally at random, but it's not far off. Here was my logic:

• The actual alert gets shown in red, the colour of errors.
• The description that goes along with it to describe a possible course of action is orange, to look like a lesser part of the error.
• The suggestions are in blue to highlight that you might want to copy/paste them.
• Everything else is in the default colour.

The warning is rendered separately in yellow.

I'm open to suggestions: unifying the description colour with the warning might make sense, for example, and I'm not tied to blue for the suggestions. (We could also bold them instead of changing colour.)

[mrnugget]

I'm open to suggestions: unifying the description colour with the warning might make sense, for example, and I'm not tied to blue for the suggestions. (We could also bold them instead of changing colour.)

I think having the description in red also makes sense, since you could then visually group the messages: yellow warning because it didn't find anything, red error shows why it didn't find anything, then suggestions.

But don't feel blocked by this comment. I think the code can be merged. If you do have an idea to improve the colors though, go for it. If not, we can fix it later.

[LawnGnome]

I made two changes, and they look like this:

I adopted @mrnugget's suggestion of unifying the alert and description colours, and I think it looks good, so let's go with that. I also added an indent on the lines past the alert — as long as the emoji is rendered as a double-width character (which I think is true on most platforms), the alert will now appear together.

[mrnugget]

Looks good! Feel free to merge.

[mrnugget]

@LawnGnome Can you add a CHANGELOG.md entry?

[LawnGnome]

@LawnGnome Can you add a CHANGELOG.md entry?

Yep, doing it now.