Add support for opt-in download to exec and run (tj#685)

* Rework argument parsing to allow options after exec and run

* Add option for run and exec to download missing version

* Reword download to cover wider functionality

* Be consistent with inner spacing of arrays

* Add download test for run and exec

bin/n

@@ -115,9 +115,9 @@ if [ -n "$HTTP_USER" ];then
   if [ -z "$HTTP_PASSWORD" ]; then
     abort "Must specify HTTP_PASSWORD when supplying HTTP_USER"
   fi
-  CURL_OPTIONS+=("-u $HTTP_USER:$HTTP_PASSWORD")
-  WGET_OPTIONS+=("--http-password=$HTTP_PASSWORD"
-                "--http-user=$HTTP_USER")
+  CURL_OPTIONS+=( "-u $HTTP_USER:$HTTP_PASSWORD" )
+  WGET_OPTIONS+=( "--http-password=$HTTP_PASSWORD"
+                "--http-user=$HTTP_USER" )
 elif [ -n "$HTTP_PASSWORD" ]; then
   abort "Must specify HTTP_USER when supplying HTTP_PASSWORD"
 fi
@@ -128,7 +128,7 @@ g_active_node=
 # set by various lookups to allow mixed logging and return value from function, especially for engine and node
 g_target_node=
 
-ACTIVATE=true
+DOWNLOAD=false # set to opt-out of activate (install), and opt-in to download (run, exec)
 ARCH=
 SHOW_VERBOSE_LOG="true"
 
@@ -387,7 +387,7 @@ Options:
   -h, --help            Display help information
   -p, --preserve        Preserve npm and npx during install of Node.js
   -q, --quiet           Disable curl output. Disable log messages processing "auto" and "engine" labels.
-  -d, --download        Download only
+  -d, --download        Download if necessary, and don't make active
   -a, --arch            Override system architecture
   --all                 ls-remote displays all matches instead of last 20
   --insecure            Turn off certificate checking for https requests (may be needed from behind a proxy server)
@@ -764,7 +764,7 @@ install() {
 
   if test -d "$dir"; then
     if [[ ! -e "$dir/n.lock" ]] ; then
-      if "$ACTIVATE" ; then
+      if [[ "$DOWNLOAD" == "false" ]] ; then
         activate "${g_mirror_folder_name}/${version}"
       fi
       exit
@@ -792,7 +792,7 @@ install() {
 
   disable_pax_mprotect bin/node
 
-  if "$ACTIVATE" ; then
+  if [[ "$DOWNLOAD" == "false" ]]; then
     activate "${g_mirror_folder_name}/$version"
   fi
 }
@@ -893,6 +893,9 @@ function find_cached_version() {
 
   update_mirror_settings_for_version "$1"
   g_cached_version="${CACHE_DIR}/${g_mirror_folder_name}/${version}"
+  if [[ ! -d "${g_cached_version}" && "${DOWNLOAD}" == "true" ]]; then
+    install "${version}"
+  fi
   [[ -d "${g_cached_version}" ]] || abort "'$1' (${version}) not in downloads cache"
 }
 
@@ -1527,14 +1530,15 @@ function show_diagnostics() {
 # which feel pretty natural.
 
 unprocessed_args=()
+positional_arg="false"
 
 while [[ $# -ne 0 ]]; do
   case "$1" in
     --all) N_MAX_REMOTE_MATCHES=32000 ;;
     -V|--version) display_n_version ;;
     -h|--help|help) display_help; exit ;;
     -q|--quiet) set_quiet ;;
-    -d|--download) ACTIVATE=false ;;
+    -d|--download) DOWNLOAD="true" ;;
     --insecure) set_insecure ;;
     -p|--preserve) N_PRESERVE_NPM="true" ;;
     --no-preserve) N_PRESERVE_NPM="" ;;
@@ -1544,9 +1548,17 @@ while [[ $# -ne 0 ]]; do
     --stable) display_remote_versions lts; exit ;; # [sic] old terminology
     --lts) display_remote_versions lts; exit ;;
     -a|--arch) shift; set_arch "$1";; # set arch and continue
-    exec) unprocessed_args=("$@"); break ;;
-    run|as|use) unprocessed_args=("$@"); break ;;
-    *) unprocessed_args+=( "$1" ) ;;
+    exec|run|as|use)
+      unprocessed_args+=( "$1" )
+      positional_arg="true"
+      ;;
+    *)
+      if [[ "${positional_arg}" == "true" ]]; then
+        unprocessed_args+=( "$@" )
+        break
+      fi
+      unprocessed_args+=( "$1" )
+      ;;
   esac
   shift
 done

test/tests/run-which.bats

@@ -11,13 +11,13 @@ function setup_file() {
   export N_PREFIX="${tmpdir}/n/test/run-which"
   n --download 4.9.1
   n --download lts
+  # using "latest" for download tests with run and exec
 }
 
 function teardown_file() {
   rm -rf "${N_PREFIX}"
 }
 
-
 @test "setupAll for run/which/exec # (2 installs)" {
   # Dummy test so setupAll displayed while running first setup
   [ -d "${N_PREFIX}/n/versions/node/4.9.1" ]
@@ -37,19 +37,16 @@ function teardown_file() {
   assert_equal "$output" "${N_PREFIX}/n/versions/node/4.9.1/bin/node"
 }
 
-
 @test "n bin v4.9.1" {
   output="$(n bin v4.9.1)"
   assert_equal "$output" "${N_PREFIX}/n/versions/node/4.9.1/bin/node"
 }
 
-
 @test "n which argon" {
   output="$(n which argon)"
   assert_equal "$output" "${N_PREFIX}/n/versions/node/4.9.1/bin/node"
 }
 
-
 @test "n which lts" {
   output="$(n which lts)"
   local LTS_VERSION="$(display_remote_version lts)"
@@ -64,26 +61,29 @@ function teardown_file() {
   assert_equal "$output" "v4.9.1"
 }
 
-
 @test "n run lts" {
   output="$(n run lts --version)"
   local LTS_VERSION="$(display_remote_version lts)"
   assert_equal "$output" "v${LTS_VERSION}"
 }
 
-
 @test "n use 4" {
   output="$(n use 4 --version)"
   assert_equal "$output" "v4.9.1"
 }
 
-
 @test "n as 4" {
   output="$(n as 4 --version)"
   assert_equal "$output" "v4.9.1"
 }
 
-
+@test "n run --download latest" {
+  n rm latest || true
+  n run --download latest --version
+  output="$(n run latest --version)"
+  local LATEST_VERSION="$(display_remote_version latest)"
+  assert_equal "$output" "v${LATEST_VERSION}"
+}
 
 
 # n exec
@@ -93,15 +93,21 @@ function teardown_file() {
   assert_equal "$output" "v4.9.1"
 }
 
-
 @test "n exec 4 npm" {
   output="$(n exec 4 npm --version)"
   assert_equal "$output" "2.15.11"
 }
 
-
 @test "n exec lts" {
   output="$(n exec lts node --version)"
   local LTS_VERSION="$(display_remote_version lts)"
   assert_equal "$output" "v${LTS_VERSION}"
 }
+
+@test "n exec -d latest" {
+  n rm latest || true
+  n exec -d latest node --version
+  output="$(n exec latest node --version)"
+  local LATEST_VERSION="$(display_remote_version latest)"
+  assert_equal "$output" "v${LATEST_VERSION}"
+}