Commit 3bfbc37dbf37095816eda500f3f1e05cb98bb95b | the-knife

author	Julius Marminge <julius0216@outlook.com> 2026-10-08 16:39:48-07:00
committer	GitHub <noreply@github.com> 2026-10-08 16:39:48-07:00
log	3bfbc37dbf37095816eda500f3f1e05cb98bb95b
tree	c636ab62532b8977d6098feb805a32bc18445c54
parent	66298aa926e6a4c95ebecbc576a68634315899c0
signature	Signed by PGP key B5690EEEBB952194

fix(desktop): the t3 command warns instead of installing behind another t3 (#17351)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

4 files changed, 57 insertions(+), 15 deletions(-)

apps
- desktop
  - src
    app
    DesktopCliCommand.test.ts
    DesktopCliCommand.ts
- web
  - src
    components
    settings
    CliCommandSettingsRow.tsx
packages
- contracts
  - src
    ipc.ts

apps/desktop/src/app/DesktopCliCommand.test.ts+24-8

 @@ -1,5 +1,5 @@
 import * as NodeServices from "@effect/platform-node/NodeServices";
-import { expect, it } from "@effect/vitest";
+import { afterEach, beforeEach, expect, it } from "@effect/vitest";
 import * as Effect from "effect/Effect";
 import * as FileSystem from "effect/FileSystem";
 import * as Option from "effect/Option";
 @@ -85,6 +85,15 @@ const fakePowerShell = (initial: string) => {
   return { registry, spawner };
 };
+// The machine's own PATH may already hold a t3; each test sets the PATH it means.
+const machinePath = process.env.PATH;
+beforeEach(() => {
+  process.env.PATH = "";
+});
+afterEach(() => {
+  process.env.PATH = machinePath;
+});
 it.layer(NodeServices.layer)("DesktopCliCommand", (it) => {
   it.effect("links the launcher onto PATH and removes only that link", () =>
     Effect.gen(function* () {
 @@ -165,7 +174,7 @@ it.layer(NodeServices.layer)("DesktopCliCommand", (it) => {
     }).pipe(Effect.scoped),
   );
-  it.effect("reports when another t3 earlier on PATH would run instead", () =>
+  it.effect("refuses to install behind another t3 that runs first", () =>
     Effect.gen(function* () {
       const fs = yield* FileSystem.FileSystem;
       const path = yield* Path.Path;
 @@ -173,16 +182,23 @@ it.layer(NodeServices.layer)("DesktopCliCommand", (it) => {
       const shadow = path.join(home, "shadow");
       yield* fs.makeDirectory(shadow);
       yield* fs.writeFileString(path.join(shadow, "t3"), "#!/bin/sh\n", { mode: 0o755 });
-      const previous = process.env.PATH;
       process.env.PATH = [shadow, path.join(home, ".local", "bin")].join(":");
-      yield* Effect.addFinalizer(() => Effect.sync(() => (process.env.PATH = previous)));
       const command = yield* commandIn({ home });
+      const theirs = path.join(shadow, "t3");
+      expect((yield* command.state).shadowedBy).toBe(theirs);
+      // A link behind it would never run, so nothing is created.
+      const error = yield* Effect.flip(command.install);
+      expect(error.message).toContain(theirs);
+      expect(yield* fs.exists(path.join(home, ".local", "bin", "t3"))).toBe(false);
+      yield* fs.remove(theirs);
       const installed = yield* command.install;
-      expect(installed.installedPath).toBe(path.join(home, ".local", "bin", "t3"));
+      expect(installed).toMatchObject({
-      expect(installed.onPath).toBe(false);
+        onPath: true,
-      yield* fs.remove(path.join(shadow, "t3"));
+        installedPath: path.join(home, ".local", "bin", "t3"),
-      expect((yield* command.state).onPath).toBe(true);
+      });
+      expect(installed.shadowedBy).toBeUndefined();
     }).pipe(Effect.scoped),
   );

apps/desktop/src/app/DesktopCliCommand.ts+21-2

 @@ -146,6 +146,14 @@ export const make = Effect.gen(function* () {
     return Option.none<string>();
   });
+  /** The `t3` a new shell runs when it is not this app's, on Unix. */
+  const foreignFirstOnPath = Effect.gen(function* () {
+    if (windows) return Option.none<string>();
+    const first = yield* firstOnPath;
+    if (Option.isNone(first) || (yield* isOurLink(first.value))) return Option.none<string>();
+    return first;
+  });
   /** Where this app's command is installed now, if anywhere. */
   const installedAt = Effect.gen(function* () {
     if (windows) {
 @@ -167,12 +175,16 @@ export const make = Effect.gen(function* () {
       return { supported: false, installedPath: null, onPath: false } as const;
     }
     const installed = yield* installedAt;
-    if (Option.isNone(installed)) return { supported: true, installedPath: null, onPath: false };
+    const shadowedBy = yield* foreignFirstOnPath;
+    const shadow = Option.isSome(shadowedBy) ? { shadowedBy: shadowedBy.value } : {};
+    if (Option.isNone(installed)) {
+      return { supported: true, installedPath: null, onPath: false, ...shadow };
+    }
     // On Windows only terminals opened after the change see it. On Unix the
     // first `t3` on PATH must be ours; a `t3` earlier on PATH would shadow it.
     const first = yield* firstOnPath;
     const onPath = windows || (Option.isSome(first) && (yield* isOurLink(first.value)));
-    return { supported: true, installedPath: installed.value, onPath };
+    return { supported: true, installedPath: installed.value, onPath, ...shadow };
   }).pipe(Effect.orElseSucceed(() => ({ supported: false, installedPath: null, onPath: false })));
   /** Writes the launcher if the app has not yet, e.g. when no local backend runs. */
 @@ -209,6 +221,13 @@ export const make = Effect.gen(function* () {
         .remove(existing.value)
         .pipe(Effect.mapError(() => fail(`Could not replace ${existing.value}.`)));
     }
+    // A link behind another `t3` never runs, so installing one would only hide the problem.
+    const shadowedBy = yield* foreignFirstOnPath;
+    if (Option.isSome(shadowedBy)) {
+      return yield* fail(
+        `Another t3 at ${shadowedBy.value} runs first in a new terminal. Remove it, or run the launcher directly at ${launcher}.`,
+      );
+    }
     const onPath = pathEntries(process.env.PATH, ":");
     const candidates = unixCandidates(environment.homeDirectory, environment.platform);
     // Prefer a folder already on PATH that the user can write to without admin rights.

apps/web/src/components/settings/CliCommandSettingsRow.tsx+7-5

...	@@ -51,11 +51,13 @@ export function CliCommandSettingsRow() {	...	@@ -51,11 +51,13 @@ export function CliCommandSettingsRow() {
51		51
52	if (!bridge \|\| !state?.supported) return null;	52	if (!bridge \|\| !state?.supported) return null;
53	const installed = state.installedPath !== null;	53	const installed = state.installedPath !== null;
54	const description = !installed	54	const description = state.shadowedBy
55	? "Run T3 Code's CLI as `t3` from any terminal."	55	? `Another t3 at ${state.shadowedBy} runs first in a new terminal. Remove it to use T3 Code's.`
56	: state.onPath	56	: !installed
57	? `Installed at ${state.installedPath}. Open a new terminal to use it.`	57	? "Run T3 Code's CLI as `t3` from any terminal."
58	: `Installed at ${state.installedPath}, which is not on your PATH yet. Add its folder to your PATH to run \`t3\`.`;	58	: state.onPath
		59	? `Installed at ${state.installedPath}. Open a new terminal to use it.`
		60	: `Installed at ${state.installedPath}, which is not on your PATH yet. Add its folder to your PATH to run \`t3\`.`;
59		61
60	return (	62	return (
61	<SettingsRow	63	<SettingsRow

packages/contracts/src/ipc.ts+5

 @@ -325,6 +325,11 @@ export const DesktopCliCommandStateSchema = Schema.Struct({
   installedPath: Schema.NullOr(Schema.String),
   /** Whether a new terminal finds it; false when the folder is not on PATH yet. */
   onPath: Schema.Boolean,
+  /**
+   * Another `t3` a new terminal runs instead, earlier on PATH. Install refuses
+   * while it is there, since a link behind it would never run.
+   */
+  shadowedBy: Schema.optionalKey(Schema.String),
 });
 export type DesktopCliCommandState = typeof DesktopCliCommandStateSchema.Type;