Normalize Windows PWD before nvm install

.buildkite/hooks/pre-command

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+# Allow for the creation of an .nvmrc file in the CI machine.
+# This allows testing the plugin fallback to .nvmrc without a confusing instance in the repo root.
+
+set -euo pipefail
+
+if [[ -z "${NVM_BUILDKITE_PLUGIN_TEST_NVMRC_VERSION:-}" ]]; then
+    exit 0
+fi
+
+printf '%s\n' "$NVM_BUILDKITE_PLUGIN_TEST_NVMRC_VERSION" > .nvmrc

.buildkite/pipeline.yml

@@ -1,4 +1,6 @@
 steps:
+  - command: make test
+
   - command: make validate
 
   - label: ":node: Validate {{ matrix.node }} via version property"
@@ -23,8 +25,40 @@ steps:
           - mac
           - default
 
-  - label: ":node: Do nothing when no .nvmrc and no Node.js version specified"
-    command: echo noop
+  - label: ":windows: :node: Validate {{ matrix.node }} on Windows"
+    command: bash .buildkite/verify_node.sh {{ matrix.node }}
+    env:
+      # nvm v0.39.4 hangs on the Windows agent when no .nvmrc exists in the
+      # working directory: its ancestor walk for one loops forever under the
+      # agent's bash. The version property below still drives the install; this
+      # .nvmrc only exists to short-circuit that walk.
+      NVM_BUILDKITE_PLUGIN_TEST_NVMRC_VERSION: "{{ matrix.node }}"
+    plugins:
+      - automattic/nvm#${BUILDKITE_COMMIT}:
+          version: "{{ matrix.node }}"
+    agents:
+      queue: windows
+    matrix:
+      setup:
+        node:
+          - v20.19.5
+          - v24.15.0
+
+  - label: ":windows: :node: Validate .nvmrc fallback on Windows"
+    env:
+      # Create an .nvmrc file to verify the plugin reads it
+      NVM_BUILDKITE_PLUGIN_TEST_NVMRC_VERSION: 20.19.5
+    command: bash .buildkite/verify_node.sh "$(cat .nvmrc)"
+    plugins:
+      - automattic/nvm#${BUILDKITE_COMMIT}
+    agents:
+      queue: windows
+
+  - label: ":node: Validate .nvmrc fallback" 
+    env:
+      # Create an .nvmrc file to verify the plugin reads it
+      NVM_BUILDKITE_PLUGIN_TEST_NVMRC_VERSION: 24.18.0
+    command: .buildkite/verify_node.sh "$(cat .nvmrc)"
     plugins:
       - automattic/nvm#${BUILDKITE_COMMIT}
 

.buildkite/verify_node.sh

@@ -14,7 +14,16 @@ echo "Checking if the active Node.js version is '$1'"
 expected_version=$(nvm version-remote "$1")
 echo "'$1' is resolved to the Node.js version $expected_version"
 
-current_version=$(nvm current)
-echo "Currently activated Node.js version is $current_version"
+# On Windows, `nvm current` reports `system` after `--no-use`; PATH has the real version.
+case "$(uname -s 2>/dev/null || true)" in
+    CYGWIN* | MINGW* | MSYS*)
+        current_version=$(node --version)
+        echo "Current node executable version is $current_version"
+        ;;
+    *)
+        current_version=$(nvm current)
+        echo "Currently activated Node.js version is $current_version"
+        ;;
+esac
 
 test "$current_version" == "$expected_version"

AGENTS.md

@@ -0,0 +1 @@
+Use `make test` for shell helper tests and `make validate` for plugin schema validation.

CLAUDE.md

@@ -0,0 +1 @@
+@AGENTS.md

Makefile

@@ -1,2 +1,6 @@
+test:
+	bash tests/nvm-plugin-helpers-test.sh
+	bash tests/pre-command-smoke-test.sh
+
 validate:
 	docker run -it --rm -v "$(shell pwd):/plugin:ro" buildkite/plugin-linter --id automattic/nvm

hooks/lib/nvm-buildkite-plugin.bash

@@ -0,0 +1,78 @@
+#!/usr/bin/env bash
+
+# Sourced helper only, so no set options. Up to callers to set strict mode before loading it.
+#
+# nvm walks PWD with slash trimming, Windows paths can make that loop forever.
+# These helpers allow preventing that behavior.
+
+nvm_plugin_should_normalize_windows_pwd() {
+    local shell_name="$1"
+    local current_pwd="$2"
+
+    case "$shell_name" in
+        CYGWIN* | MINGW* | MSYS*) ;;
+        *) return 1 ;;
+    esac
+
+    case "$current_pwd" in
+        *\\* | ?:*) return 0 ;;
+        *) return 1 ;;
+    esac
+}
+
+nvm_plugin_windows_pwd_to_posix() {
+    local current_pwd="$1"
+    local drive
+    local drive_lower
+    local rest
+
+    case "$current_pwd" in
+        [A-Za-z]:*)
+            drive="${current_pwd:0:1}"
+            drive_lower="$(printf '%s' "$drive" | tr '[:upper:]' '[:lower:]')"
+            rest="${current_pwd:2}"
+            rest="${rest//\\//}"
+
+            printf '/%s%s\n' "$drive_lower" "$rest"
+            return 0
+            ;;
+        \\\\*)
+            printf '%s\n' "${current_pwd//\\//}"
+            return 0
+            ;;
+        *)
+            return 1
+            ;;
+    esac
+}
+
+nvm_plugin_normalize_windows_pwd_for_nvm() {
+    local shell_name
+    shell_name="$(uname -s 2>/dev/null || true)"
+
+    if ! nvm_plugin_should_normalize_windows_pwd "$shell_name" "${PWD:-}"; then
+        return 0
+    fi
+
+    local normalized_pwd
+    if ! normalized_pwd="$(nvm_plugin_windows_pwd_to_posix "$PWD")"; then
+        echo "Cannot normalize Windows PWD for nvm from ${PWD}"
+        return 0
+    fi
+
+    if [[ -z "$normalized_pwd" || "$normalized_pwd" == "$PWD" ]]; then
+        echo "Cannot normalize Windows PWD for nvm from ${PWD}"
+        return 0
+    fi
+
+    if [[ ! -d "$normalized_pwd" ]]; then
+        echo "Cannot normalize Windows PWD for nvm because ${normalized_pwd} is not a directory"
+        return 0
+    fi
+
+    echo "Normalizing Windows PWD for nvm from ${PWD} to ${normalized_pwd}"
+    cd "$normalized_pwd" || {
+        echo "Failed to normalize Windows PWD for nvm to ${normalized_pwd}"
+        return 0
+    }
+}

hooks/pre-command

@@ -2,6 +2,10 @@
 
 set -euo pipefail
 
+plugin_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+# shellcheck source=hooks/lib/nvm-buildkite-plugin.bash
+source "$plugin_dir/hooks/lib/nvm-buildkite-plugin.bash"
+
 echo "~~~ :node: Installing nvm"
 
 [[ -f .nvmrc || -n "${BUILDKITE_PLUGIN_NVM_VERSION:-}" ]] || {
@@ -37,6 +41,8 @@ echo "Installing nvm in $NVM_DIR"
 
 curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.4/install.sh | PROFILE=/dev/null bash
 
+nvm_plugin_normalize_windows_pwd_for_nvm
+
 # shellcheck source=/dev/null
 source "$NVM_DIR/nvm.sh" --no-use
 

tests/nvm-plugin-helpers-test.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+# shellcheck source=hooks/lib/nvm-buildkite-plugin.bash
+source "$repo_root/hooks/lib/nvm-buildkite-plugin.bash"
+
+fail() {
+    echo "FAIL: $*" >&2
+    exit 1
+}
+
+nvm_plugin_should_normalize_windows_pwd "MSYS_NT-10.0" 'C:\buildkite-agent\repo' || fail "MSYS backslash PWD should be normalized"
+nvm_plugin_should_normalize_windows_pwd "CYGWIN_NT-10.0" 'C:/buildkite-agent/repo' || fail "Cygwin drive PWD should be normalized"
+
+if nvm_plugin_should_normalize_windows_pwd "MSYS_NT-10.0" "/c/buildkite-agent/repo"; then
+    fail "MSYS POSIX PWD should not be normalized"
+fi
+
+if nvm_plugin_should_normalize_windows_pwd "linux-gnu" 'C:\buildkite-agent\repo'; then
+    fail "non-Windows shell PWD should not be normalized"
+fi
+
+[[ "$(nvm_plugin_windows_pwd_to_posix 'C:\buildkite-agent\repo')" == "/c/buildkite-agent/repo" ]] || fail "backslash drive path should convert to POSIX path"
+[[ "$(nvm_plugin_windows_pwd_to_posix 'D:/buildkite-agent/repo')" == "/d/buildkite-agent/repo" ]] || fail "slash drive path should convert to POSIX path"
+[[ "$(nvm_plugin_windows_pwd_to_posix '\\server\share\repo')" == "//server/share/repo" ]] || fail "UNC path should convert to POSIX path"
+
+if nvm_plugin_windows_pwd_to_posix "/c/buildkite-agent/repo" >/dev/null; then
+    fail "POSIX path should not be converted"
+fi
+
+echo "All helper tests passed."

tests/pre-command-smoke-test.sh

@@ -0,0 +1,71 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+tmpdir="$(mktemp -d)"
+trap 'rm -rf "$tmpdir"' EXIT
+
+mkdir -p "$tmpdir/bin" "$tmpdir/work"
+
+cat > "$tmpdir/bin/curl" <<'CURL'
+#!/usr/bin/env bash
+cat <<'INSTALLER'
+#!/usr/bin/env bash
+mkdir -p "$NVM_DIR"
+cat > "$NVM_DIR/nvm.sh" <<'NVM'
+nvm() {
+    case "$1" in
+        install)
+            echo "fake nvm install ${*:2}"
+            ;;
+        use)
+            echo "fake nvm use ${*:2}"
+            ;;
+        *)
+            echo "unsupported nvm command: $*" >&2
+            return 1
+            ;;
+    esac
+}
+NVM
+INSTALLER
+CURL
+chmod +x "$tmpdir/bin/curl"
+
+cat > "$tmpdir/bin/node" <<'NODE'
+#!/usr/bin/env bash
+if [[ "${1:-}" == "--version" ]]; then
+    echo "v20.19.5"
+elif [[ "${1:-}" == "-" ]]; then
+    cat >/dev/null
+    echo "Hello Node.js"
+else
+    echo "unsupported node command: $*" >&2
+    exit 1
+fi
+NODE
+chmod +x "$tmpdir/bin/node"
+
+(
+    export NVM_BUILDKITE_PLUGIN_TEST_NVMRC_VERSION=20.19.5
+
+    cd "$tmpdir/work"
+    bash "$repo_root/.buildkite/hooks/pre-command"
+)
+
+(
+    export PATH="$tmpdir/bin:$PATH"
+    export BUILDKITE_JOB_ID="pre-command-smoke"
+    export TMPDIR="$tmpdir/tmp"
+    mkdir -p "$TMPDIR"
+
+    cd "$tmpdir/work"
+    bash "$repo_root/hooks/pre-command"
+) > "$tmpdir/pre-command.out"
+
+grep -F "fake nvm install --no-progress" "$tmpdir/pre-command.out" >/dev/null
+grep -F "fake nvm use" "$tmpdir/pre-command.out" >/dev/null
+grep -F "Node.js and nvm successfully set up." "$tmpdir/pre-command.out" >/dev/null
+
+echo "pre-command smoke test passed."