Expand ~ in path options from the config file

[harshbhx]

Fixes #7051

Summary

Expand a leading ~ in path options (such as user-data-dir and extensions-dir) so they work in config.yaml the same way they do on the command line.

Problem

The shell expands ~ in command-line arguments, but nothing expands it in values read from the config file. With

user-data-dir: ~/.config/code-server-data

the value reaches path.resolve as-is (src/node/cli.ts#L469) and is resolved against the current working directory. Depending on where code-server is started, the result is <cwd>/~/.config/code-server-data or /~/.config/..., which leads to errors like:

Unable to read file '/~/.config/code-server-user-data/extensions/extensions.json'

Solution

As suggested in the issue ("it would be nice if we manually expand it when we read the config"), path options now go through a small expandTilde helper before path.resolve:

• ~ → the home directory
• ~/foo (or ~\foo on Windows) → <home>/foo
• everything else, including ~user/... and a ~ in the middle of a path, is left unchanged

Because the expansion happens in parse, it covers every option marked path: true (user-data-dir, extensions-dir, builtin-extensions-dir, cert, cert-key, socket, i18n), whether it comes from the CLI or the config file. CLI values are already expanded by the shell, so the change is a no-op for them.

Changes

File	Change
src/node/util.ts	Add expandTilde()
src/node/cli.ts	Call expandTilde() before path.resolve() for path options
test/unit/node/util.test.ts	Unit tests for expandTilde()
test/unit/node/cli.test.ts	Test that parseConfigFile expands ~ in user-data-dir and extensions-dir

Before / After

config.yaml:

user-data-dir: ~/.config/code-server-data

	Resolved user-data-dir (started from /srv)
Before	/srv/~/.config/code-server-data
After	/home/<user>/.config/code-server-data

How to test

1. Put user-data-dir: ~/.config/code-server-data in ~/.config/code-server/config.yaml.
2. cd /tmp && code-server
3. Check that the data directory is ~/.config/code-server-data in your home and that no /tmp/~ directory was created.

Testing done

• New tests in util.test.ts and cli.test.ts
• cli and util unit test suites: 144/144 passing
• The new config test fails when expandTilde is a no-op, so it covers the bug
• prettier --check and eslint clean on the changed files
• Not tested on Windows (the ~\ branch is covered only by the path.sep check)

Notes for reviewers

• ~user expansion is intentionally not supported; it would need a user database lookup and isn't what the issue asks for.
• Positional arguments (_) aren't path options and are unchanged.

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