## Summary of the Pull Request
Adds support for commandline arguments to the Windows Terminal, in accordance with the spec in #3495
## References
* Original issue: #607
* Original spec: #3495
## PR Checklist
* [x] Closes#607
* [x] I work here
* [x] Tests added/passed
* [ ] We should probably add some docs on these commands
* [x] The spec (#3495) needs to be merged first!
## Detailed Description of the Pull Request / Additional comments
🛑 **STOP** 🛑 - have you read #3495 yet? If you haven't, go do that now.
This PR adds support for three initial sub-commands to the `wt.exe` application:
* `new-tab`: Used to create a new tab.
* `split-pane`: Used to create a new split.
* `focus-tab`: Moves focus to another tab.
These commands are largely POC to prove that the commandlines work. They're not totally finished, but they work well enough. Follow up work items will be filed to track adding support for additional parameters and subcommands
Important scenarios added:
* `wt -d .`: Open a new wt instance in the current working directory #878
* `wt -p <profile name>`: Create a wt instance running the given profile, to unblock #576, #1357, #2339
* `wt ; new-tab ; split-pane -V`: Launch the terminal with multiple tabs, splits, to unblock #756
## Validation Steps Performed
* Ran tests
* Played with it a bunch
## Summary of the Pull Request
<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist
* [x] Closes#4013
* [x] I work here.
* [x] Existing tests should be OK. Real changes, just adding a lib to use.
* [x] Couldn't find any existing docs about intsafe.
* [x] Am core contributor.
## Detailed Description of the Pull Request / Additional comments
* [x] Can we remove min/max completely or rename it in the two projects where it had to be reintroduced? This is now moved into #4152
* [x] How many usages of the old safe math are there? **79**
* [x] If not a ton, can we migrate them here or in a follow on PR? This is now moved into #4153
Files with old safe math:
- TerminalControl: TSFInputControl.cpp
- TerminalCore: TerminalDispatch.cpp
- TerminalCore: TerminalSelection.cpp
- Host: directio.cpp
- RendererGdi: invalidate.cpp
- RendererGdi: math.cpp
- RendererGdi: paint.cpp
- RendererVt: paint.cpp
- TerminalAdapter: adaptDispatch.cpp
- Types: viewport.cpp
- Types: WindowUiaProviderBase.cpp
## Validation Steps Performed
Switch to using jsoncpp as our json library. This lets us pretty-print the json file by default, and lets users place comments in the json file.
We will now only re-write the file when the actual logical structure of the json object changes, not only when the serialization changes.
Unfortunately, this will remove any existing ordering of profiles, and make the order random. We don't terribly care though, because when #754 lands, this will be less painful.
It also introduces a top-level globals object to hold all the global properties, including keybindings. Existing profiles should gracefully upgrade.
