test: add e2e coverage for issue #1527 repro steps

.changeset/cuddly-cars-ring.md

@@ -0,0 +1,5 @@
+---
+"fnm": patch
+---
+
+prefer explicit shell flags in installer-generated shell setup and fix ARM installer CI platform selection

.ci/install.sh

@@ -177,7 +177,7 @@ setup_shell() {
       if [ "$USE_HOMEBREW" != "true" ]; then
         echo '  export PATH="$FNM_PATH:$PATH"'
       fi
-      echo '  eval "`fnm env`"'
+      echo '  eval "$(fnm env --shell zsh)"'
       echo 'fi'
     } | tee -a "$CONF_FILE"
 
@@ -193,7 +193,7 @@ setup_shell() {
       if [ "$USE_HOMEBREW" != "true" ]; then
         echo '  set PATH "$FNM_PATH" $PATH'
       fi
-      echo '  fnm env | source'
+      echo '  fnm env --shell fish | source'
       echo 'end'
     } | tee -a "$CONF_FILE"
 
@@ -213,7 +213,7 @@ setup_shell() {
       if [ "$USE_HOMEBREW" != "true" ]; then
         echo '  export PATH="$FNM_PATH:$PATH"'
       fi
-      echo '  eval "`fnm env`"'
+      echo '  eval "$(fnm env --shell bash)"'
       echo 'fi'
     } | tee -a "$CONF_FILE"
 

.github/workflows/installation_script.yml

@@ -1,5 +1,5 @@
 name: Installation script
-on: 
+on:
   pull_request:
     paths:
       - .ci/install.sh
@@ -13,9 +13,11 @@ jobs:
   test_against_latest_release_arm:
     strategy:
       matrix:
-        docker_image:
-          - arm64v8/ubuntu
-          - arm32v7/ubuntu
+        include:
+          - docker_image: arm64v8/ubuntu
+            docker_platform: linux/arm64/v8
+          - docker_image: arm32v7/ubuntu
+            docker_platform: linux/arm/v7
     name: Test against latest release (ARM)
     runs-on: ubuntu-latest
     steps:
@@ -25,7 +27,7 @@ jobs:
       - uses: actions/checkout@v4
       - name: Run installation script in Docker
         run: |
-          docker run --rm -v $(pwd):$(pwd) -e "RUST_LOG=fnm=debug" --workdir $(pwd) ${{matrix.docker_image}} bash -c '
+          docker run --rm --platform ${{ matrix.docker_platform }} -v $(pwd):$(pwd) -e "RUST_LOG=fnm=debug" --workdir $(pwd) ${{matrix.docker_image}} bash -c '
             set -e
 
             apt update && apt install -y unzip curl libatomic1
@@ -53,13 +55,13 @@ jobs:
     strategy:
       matrix:
         shell: [fish, zsh, bash]
-        setup: 
+        setup:
           - os: ubuntu
-            script_arguments: ''
+            script_arguments: ""
           - os: macos
-            script_arguments: ''
+            script_arguments: ""
           - os: macos
-            script_arguments: '--force-no-brew'
+            script_arguments: "--force-no-brew"
     runs-on: ${{ matrix.setup.os }}-latest
     steps:
       - uses: actions/checkout@v4
@@ -84,4 +86,4 @@ jobs:
       - run: "env SHELL=$(which ${{ matrix.shell }}) bash ./.ci/install.sh ${{ matrix.setup.script_arguments }}"
         name: Run the installation script
       - run: ./.ci/test_installation_script.sh ${{ matrix.shell }}
-        name: 'Test installation script'
+        name: "Test installation script"

README.md

@@ -136,6 +136,9 @@ Please follow your shell instructions to install them.
 Environment variables need to be setup before you can start using fnm.
 This is done by evaluating the output of `fnm env`.
 
+> [!TIP]
+> Prefer passing an explicit shell (for example `fnm env --shell bash`) instead of relying on shell inference at runtime. It is a bit faster and avoids process tree detection.
+
 > [!NOTE]
 > Check out the [Configuration](./docs/configuration.md) section to enable highly
 > recommended features, like automatic version switching.
@@ -197,7 +200,7 @@ fnm env --use-on-cd --shell powershell | Out-String | Invoke-Expression
 
 #### Windows Command Prompt aka Batch aka WinCMD
 
-fnm is also supported but is not entirely covered. You can set up a startup script for [cmd.exe]( https://superuser.com/a/144348) or [Windows Terminal](https://superuser.com/a/1855283) and append the following lines:
+fnm is also supported but is not entirely covered. You can set up a startup script for [cmd.exe](https://superuser.com/a/144348) or [Windows Terminal](https://superuser.com/a/1855283) and append the following lines:
 
 ```batch
 @echo off

docs/commands.md

@@ -380,7 +380,7 @@ Print and set up required environment variables for fnm
 
 This command generates a series of shell commands that should be evaluated by your shell to create a fnm-ready environment.
 
-Each shell has its own syntax of evaluating a dynamic expression. For example, evaluating fnm on Bash and Zsh would look like `eval "$(fnm env)"`. In Fish, evaluating would look like `fnm env | source`
+Each shell has its own syntax of evaluating a dynamic expression. For example, evaluating fnm on Bash and Zsh would look like `eval "$(fnm env --shell bash)"`. In Fish, evaluating would look like `fnm env --shell fish | source`
 
 Usage: fnm env [OPTIONS]
 

e2e/repros/issue-1527.test.ts

@@ -0,0 +1,65 @@
+import { writeFile } from "node:fs/promises"
+import path from "node:path"
+import { script } from "../shellcode/script.js"
+import { Bash, Fish, PowerShell, Zsh } from "../shellcode/shells.js"
+import describe from "../describe.js"
+import testCwd from "../shellcode/test-cwd.js"
+
+const findCowsayInPath = `
+const fs = require("node:fs")
+const path = require("node:path")
+
+const pathEntries = (process.env.PATH || "").split(path.delimiter)
+const candidates = process.platform === "win32"
+  ? ["cowsay.cmd", "cowsay.exe", "cowsay"]
+  : ["cowsay"]
+
+let found = false
+for (const entry of pathEntries) {
+  for (const candidate of candidates) {
+    if (fs.existsSync(path.join(entry, candidate))) {
+      found = true
+      break
+    }
+  }
+
+  if (found) {
+    break
+  }
+}
+
+console.log(found ? "found" : "missing")
+`
+
+for (const shell of [Bash, Zsh, Fish, PowerShell]) {
+  describe(shell, () => {
+    test(`issue #1527: cowsay is not in PATH after uninstall on node 16`, async () => {
+      const checkPathScript = path.join(testCwd(), "check-cowsay-in-path.js")
+      await writeFile(checkPathScript, findCowsayInPath)
+
+      await script(shell)
+        .then(shell.env({}))
+        .then(shell.call("fnm", ["install", "16"]))
+        .then(shell.call("fnm", ["install", "18"]))
+        .then(shell.call("fnm", ["use", "16"]))
+        .then(shell.call("npm", ["install", "-g", "cowsay"]))
+        .then(shell.call("fnm", ["use", "18"]))
+        .then(shell.call("npm", ["install", "-g", "cowsay"]))
+        .then(shell.call("fnm", ["use", "16"]))
+        .then(
+          shell.scriptOutputContains(
+            shell.call("node", ["check-cowsay-in-path.js"]),
+            "found",
+          ),
+        )
+        .then(shell.call("npm", ["uninstall", "-g", "cowsay"]))
+        .then(
+          shell.scriptOutputContains(
+            shell.call("node", ["check-cowsay-in-path.js"]),
+            "missing",
+          ),
+        )
+        .execute(shell)
+    })
+  })
+}

src/cli.rs

@@ -27,8 +27,8 @@ pub enum SubCommand {
     /// should be evaluated by your shell to create a fnm-ready environment.
     ///
     /// Each shell has its own syntax of evaluating a dynamic expression.
-    /// For example, evaluating fnm on Bash and Zsh would look like `eval "$(fnm env)"`.
-    /// In Fish, evaluating would look like `fnm env | source`
+    /// For example, evaluating fnm on Bash and Zsh would look like `eval "$(fnm env --shell bash)"`.
+    /// In Fish, evaluating would look like `fnm env --shell fish | source`
     #[clap(name = "env", bin_name = "env")]
     Env(commands::env::Env),