Add VS Code create new project command by joshka · Pull Request #22103 · rust-lang/rust-analyzer

joshka · 2026-04-20T02:20:37Z

Fixes #19338.

Summary

Add a VS Code-side rust-analyzer: Create New Project... command that creates a new Cargo
binary or library package from the editor.

This adds:

the rust-analyzer.newProject command
a rust-analyzer.projectCreation.openAfterCreate setting for post-create behavior
command palette and Explorer empty-state entry points
a walkthrough step
unit tests for the local validation/action-selection/argument-building logic

Behavior

The command flow is:

resolve and validate Cargo
choose Binary Application or Library
choose the parent folder
enter the project name
run cargo new
choose whether to open the project, open it in a new window, or add it to the workspace

The implementation stays entirely in the VS Code extension and does not add any rust-analyzer
server/LSP changes.

Notes and tradeoffs

Local validation is intentionally narrow. It rejects obviously invalid directory names and lets
cargo new remain the source of truth for package-name-specific validation.
The command now uses rust-analyzer's effective environment (server.extraEnv) both to resolve
and to run Cargo. While implementing this, I found a broader extension-side inconsistency where
some tool-launch paths already pass an env through but cargoPath(env) still resolved against
the VS Code host process environment. This patch makes cargoPath(env) honor the supplied env's
CARGO, PATH, and CARGO_HOME view.
Command-failure logging was adjusted to avoid dumping the merged environment. Environment
variables may contain secrets (API keys, tokens, credentials), so failures log only the command,
cwd, exit status, and stdout/stderr/error details.
The project-name prompt now shows the selected base path (for example ~/code) to make it clear
that the folder picker selects the parent directory and the project will be created underneath it.

Manual smoke tests

Tested manually for:

Empty VS Code window -> create binary project -> choose Open.
Empty VS Code window -> create library project -> choose Open in New Window.
Existing single-folder workspace -> create project -> choose Add to Workspace and confirm RA discovers it without window reload.
Existing multi-root workspace -> create project -> choose each open mode and confirm behavior matches the prompt.
Failure path with missing/broken cargo -> clear error message.
Failure path with Cargo-rejected package name -> Cargo error is shown rather than silently swallowed.
Explorer empty-state entry launches the same flow as the command palette command.

Follow-up work

Activating the extension from an empty window for rust-analyzer.newProject currently still
flips the inRustProject context to true because activation unconditionally sets that context
today. That is a broader context-management issue rather than part of the project-creation flow
itself, and should be handled as a follow-up so newProject remains available in empty windows
without exposing unrelated Rust-project-only UI.

AI disclosure

I used Codex/AI tooling to research similar editor implementations, refine the implementation plan,
review parts of the code structure, and draft/refine portions of this change. I reviewed the
resulting code and notes before opening this PR.

joshka · 2026-04-20T02:28:26Z

+/**
+ * Entry point for the `rust-analyzer: Create New Project...` command.
+ *
+ * This function keeps the user-visible workflow in one place: resolve Cargo, gather the project
+ * inputs, run `cargo new`, and then apply the requested post-create workspace action.
+ */


I intentionally steered codex to produce docs as the intent helps make the code readable IMO. Intention revealing names are good, but they don't convey tradeoffs / rationale / etc. This might be a bit noisier than most places in RA, but this is an intentional choice to improve such things.

View changes since the review

joshka · 2026-04-20T02:29:52Z

+ * inputs, run `cargo new`, and then apply the requested post-create workspace action.
+ */
+export function newProject(ctx: Ctx): Cmd {
+    return async () => {


I split this method up from a longer one that had each of the pieces in a single method. It was difficult to follow / understand. This feels a bit table of contents and similarly problematic - there's probably a good balance, but I feel this is closer to the right size than the opposite (all the helper methods inlined here).

View changes since the review

joshka · 2026-04-20T02:32:20Z

+    // Use the same effective environment rust-analyzer uses elsewhere so project creation sees
+    // toolchain wrappers, PATH overrides, and CARGO_HOME changes from configuration.
+    const cargoEnv = { ...process.env, ...ctx.config.serverExtraEnv };


This is the part I'm least familiar with being correct choices. I think it's reasonably correct based on my understanding of what is going on here, but would value a second opinion.

View changes since the review

joshka · 2026-04-20T02:34:41Z

    return async () => ctx.client.sendRequest(ra.reloadWorkspace);
 }

+type NewProjectKind = "bin" | "lib";


This is a bunch of code to dump in an existing module. I'd tend to split additive code like this into a new separate module as it cuts down the cognitive load a bit, but went with keeping with the existing convention here rather than doing that. Ideally this code probably belongs in newProject.ts

View changes since the review

joshka · 2026-04-20T02:37:24Z

+    // variables may contain secrets such as API keys, tokens, and credentials, so failure logs
+    // must not dump the merged env here.
+    const commandLine = [logContext.cargo, ...logContext.args].join(" ");
+    log.error(message);


Not sure if there's an existing better logging approach here. The initial implementation just showed a notification, but I figure that there's a bunch of failure cases where the details of what's going on in cargo invocation is likely a bit more detailed for whatever reason. Maybe it's unlikely to hit this point. This should probably be extracted to a common function somewhere. Codex didn't find an obvious existing pattern / code to reuse for this.

View changes since the review

joshka · 2026-04-20T02:38:51Z

    if (env?.["RUSTC_TOOLCHAIN"]) {
        return Promise.resolve("cargo");
    }
+    if (env) {


I'm not sure I 100% understand this part of the change.

View changes since the review

joshka · 2026-04-20T02:41:06Z

+    if (env) {
+        return getPathForExecutableWithEnv("cargo", env);
+    }


The new-project command builds an effective Cargo environment from rust-analyzer configuration (server.extraEnv) before running cargo new. Resolve cargo from that same env here so the command does not discover one Cargo binary and then execute another.

View changes since the review

Implement a rust-analyzer VS Code command for creating new Cargo projects from the editor. Add command registration, UI entry points, configuration for post-create behavior, and tests for the command flow. AI tools were used to research comparable editor behaviors and help refine the implementation plan; the resulting changes were reviewed before submission.

joshka · 2026-04-20T02:51:49Z

ChayimFriedman2 · 2026-04-20T15:43:36Z

This is a large wall of code, and I'm not even sure this feature is in scope for r-a.

joshka · 2026-04-20T16:19:33Z

This is a large wall of code, and I'm not even sure this feature is in scope for r-a.

It's working, self-reviewed, tested manually and with unit tests, with a firm spec in the linked issue that I spent time iterating on prior to throwing the tooling at it, plus refactoring and improving the generated code.

It exists because other extensions do this already, and it allows me to live in vscode rather than a terminal in order to create rust applications / libraries. This seems like a solidly good way to validate whether it's scope.

r-a is the place where rust projects live in vscode. From that perspective creating a new rust project in vscode should live in r-a.

stefnotch · 2026-04-22T20:47:37Z

+function displayProjectBasePath(parentFolder: vscode.Uri): string {
+    const fsPath = parentFolder.fsPath;
+    const home = os.homedir();
+    if (fsPath === home) {


This won't ever be true on Windows, because the drive letter won't match. In general, I tend to be extremely suspicious of any path manipulation, because it's so easy to get it wrong.

Will handle UNC paths and normalize windows drive letters to lower-case
https://code.visualstudio.com/api/references/vscode-api#Uri

View changes since the review

Removed this home-relative ~ shortening for now to simplify the PR. We can re-add it later if it proves useful or necessary.

stefnotch · 2026-04-22T20:48:29Z

+
+// Keep local validation intentionally narrow: reject obviously invalid folder names up front,
+// then let `cargo new` remain the source of truth for package-name-specific rules.
+export function validateNewProjectName(


Is there any upside in doing this validation?

View changes since the review

yes - you get immediate results in the ui where it prompts for a name rather than after you hit return.

https://doc.rust-lang.org/cargo/reference/manifest.html#the-name-field

Then why not harden the check to be like cargo itself? It seems like a pretty straightforward regex.

stefnotch · 2026-04-22T20:51:51Z

+    const openNewWindow = "Open in New Window";
+    const choices = [open, openNewWindow];
+
+    const addToWorkspace = "Add to Workspace";


What does "workspace" mean in this context? Is it about adding it to the cargo workspace or about the vscode workspace?

View changes since the review

vscode workspace. This is about running cargo new. That cannot add a crate to a workspace.

I see. Would it be possible to change the wording?
If I used this cargo new command in a sub-folder of a cargo workspace, then the project would be automatically added to the cargo workspace.

At which point I'd be confused about why the extension is asking about a workspace. Until I figure out that it is asking about a vscode workspace.

stefnotch · 2026-04-22T20:55:52Z

As a general question, which other extensions do this? I don't have any extensions installed with a similar feature, except for the Typst one. Though I don't fully understand the Typst one. I think Typst does it, because it doesn't rely on a CLI?

joshka · 2026-04-22T21:59:19Z

As a general question, which other extensions do this? I don't have any extensions installed with a similar feature, except for the Typst one. Though I don't fully understand the Typst one. I think Typst does it, because it doesn't rely on a CLI?

(From the issue plan details) #19338 (comment):
I also checked several other extensions to ground the expected behavior and tradeoffs here,
including Swift, Java, Python, Go, and .NET.

Remove home-relative path shortening from the new-project prompt to avoid adding path-normalization logic for a cosmetic display detail. AI-assisted-by: OpenAI Codex

joshka commented Apr 20, 2026

View reviewed changes

joshka force-pushed the joshka/new-project-command branch from d7ff960 to 28f842e Compare April 20, 2026 02:43

joshka marked this pull request as ready for review April 20, 2026 02:52

rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Apr 20, 2026

joshka mentioned this pull request Apr 20, 2026

Create a new rust project from VSCode (cargo new / cargo init) #19338

Open

stefnotch reviewed Apr 22, 2026

View reviewed changes

Show full new-project parent paths

f8c20bf

Remove home-relative path shortening from the new-project prompt to avoid adding path-normalization logic for a cosmetic display detail. AI-assisted-by: OpenAI Codex

Conversation

joshka commented Apr 20, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Behavior

Notes and tradeoffs

Manual smoke tests

Follow-up work

AI disclosure

Uh oh!

joshka Apr 20, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka Apr 20, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka Apr 20, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka Apr 20, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka Apr 20, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka Apr 20, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka Apr 20, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka commented Apr 20, 2026

Uh oh!

ChayimFriedman2 commented Apr 20, 2026

Uh oh!

joshka commented Apr 20, 2026

Uh oh!

stefnotch Apr 22, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

stefnotch Apr 22, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka Apr 22, 2026

Choose a reason for hiding this comment

Uh oh!

stefnotch Apr 23, 2026

Choose a reason for hiding this comment

Uh oh!

stefnotch Apr 22, 2026 • edited by rustbot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

joshka Apr 22, 2026

Choose a reason for hiding this comment

Uh oh!

stefnotch Apr 23, 2026

Choose a reason for hiding this comment

Uh oh!

stefnotch commented Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

joshka commented Apr 22, 2026

Uh oh!

Reviewers

Assignees

Labels

joshka commented Apr 20, 2026 •

edited by rustbot

Loading

joshka Apr 20, 2026 •

edited by rustbot

Loading

joshka Apr 20, 2026 •

edited by rustbot

Loading

joshka Apr 20, 2026 •

edited by rustbot

Loading

joshka Apr 20, 2026 •

edited by rustbot

Loading

joshka Apr 20, 2026 •

edited by rustbot

Loading

joshka Apr 20, 2026 •

edited by rustbot

Loading

joshka Apr 20, 2026 •

edited by rustbot

Loading

stefnotch Apr 22, 2026 •

edited by rustbot

Loading

joshka Apr 22, 2026 •

edited

Loading

stefnotch Apr 22, 2026 •

edited by rustbot

Loading

stefnotch Apr 22, 2026 •

edited by rustbot

Loading

stefnotch commented Apr 22, 2026 •

edited

Loading