Terminal: Feature Request: Allow URLs to be clicked

[noinkling]

Summary of the new feature/enhancement

Detect URLs and make them clickable (open the URL in the default browser). This is a convenience feature present in many other terminals.

I believe the value is self-evident, but here's a concrete use case example regardless: when I run yarn outdated (Yarn is a package manager) it outputs a repository/homepage URL for every listed package. I want to be able to click one of those URLs to open the page quickly/easily and have a look at what has changed in the new version of the package.

Implementation details

• Probably don't need to support anything more than text starting with http:// or https://.
• URLs that span multiple lines (due to being truncated by the window width) should be handled correctly.
• There should probably be an indication that the URL is clickable, e.g. cursor change + underline on mouse hover.
• Most other terminals require an alt or ctrl click, I presume to guard against accidental clicks when copying and so forth.

You can look at something like VS Code's terminal for inspiration. Again this is all probably self-evident.

Stretch goal (covered in #204)

[zakius]

IMO it should support all schemas for the sake of completion, avoiding further issues asking for addition of new ones and reusability of the code/library.

One thing that may get complex to get right is handling of parentheses: most of implementations I've met incorrectly skip the closing parenthesis character ()) if it's the last character in the link breaking multiple Wikipedia links. Probably there should be used some parentheses matching algorithm to decide if this last character is a part of link or not.

EDIT: typo

[noinkling]

IMO it should support all schemas for the sake of completion, avoiding further issues asking for addition of new ones and reusability of the code/library.

I think the issue with that is that it's potentially a security issue since a registered protocol handler could be malicious. Maybe it just needs to follow the lead of browsers and popup a confirmation dialog when a URI has an unknown scheme/would be handled by an unknown program. There's a bit of discussion about this in the link I posted.

[zakius]

The solution I'd like to use would be detecting all schemas and adding a sanity check to click handler with ability to whitelist and blacklist in settings

[TheModdersDen]

Take a look at this: https://youtu.be/8gw0rXPMMPE?t=23. Looks like Microsoft already has this on their radar (I hope...) :)

EDIT: In case you miss it, it's the "wt install link-preview" part.

[egmontkob]

most of implementations I've met incorrectly skip the closing parenthesis character ()) if it's the last character in the link breaking multiple Wikipedia links

On the other hand, URLs are often enclosed within parentheses in text flow (see e.g. http://example.com/foobar) <- like here, and so are in Markdown files.

In gnome-terminal we addressed these two contradicting requirements by allowing parentheses () and square brackets [] as long as they occur in balanced pairs. This was implemented using recursive regular expression. See g-t 763980.

Another similar tricky case is the trailing apostrophe, see g-t 448044.

[zakius]

In gnome-terminal we addressed these two contradicting requirements by allowing parentheses () and square brackets [] as long as they occur in balanced pairs.

I mentioned that a bit later in less technical terms, that's probably the exact reason why most of implementations opt for not catching these at all over being too eager

I'm a bit worried about these rare cases when there's closing paren without matching opening one, but we can't figure this out without polling the server unfortunately

[egmontkob]

we can't figure this out without polling the server

Haha, this is also a possibility – I personally wouldn't go for it, though. I'm sure you share my concerns about data leakage as well as slowness.

It's all guesswork, there's no perfect solution (well, there's #204 to address this gap). We found the matching parens thingy to work well enough, we haven't received a report since we implemented that. At least it definitely turned out to be better than either always matching the paren or never matching. It was a bit tricky to implement, digging into rarely used and hardly known regex features of certain regex libraries (so I'm not surprised that many terminals don't bother with it), but I think it was worth it. :)

[DHowett-MSFT]

Thanks for the suggestions, all. This is actually a duplicate of #574.

[DHowett-MSFT]

I've migrated most of your comments over. Thanks.