[New] allow .nvmrc files to support comments

In theory, `npx nvmrc` can now be used to validate an `.nvmrc` file that `nvm` will support. Allowances have been made for future extensibility, and aliases may no longer contain a `#`.

Fixes #3336. Closes #2288.

Co-authored-by: Jordan Harband <ljharb@gmail.com>
Co-authored-by: Yash Singh <saiansh2525@gmail.com>

test/common.sh

@@ -101,3 +101,105 @@ watch() {
   kill %2;
   return $EXIT_CODE
 }
+
+parse_json() {
+  local json
+  json="$1"
+  local key
+  key=""
+  local value
+  value=""
+  local output
+  output=""
+  local in_key
+  in_key=0
+  local in_value
+  in_value=0
+  local in_string
+  in_string=0
+  local escaped
+  escaped=0
+  local buffer
+  buffer=""
+  local char
+  local len
+  len=${#json}
+  local arr_index
+  arr_index=0
+  local in_array
+  in_array=0
+
+  for ((i = 0; i < len; i++)); do
+    char="${json:i:1}"
+
+    if [ "$in_string" -eq 1 ]; then
+      if [ "$escaped" -eq 1 ]; then
+        buffer="$buffer$char"
+        escaped=0
+      elif [ "$char" = "\\" ]; then
+        escaped=1
+      elif [ "$char" = "\"" ]; then
+        in_string=0
+        if [ "$in_key" -eq 1 ]; then
+          key="$buffer"
+          buffer=""
+          in_key=0
+        elif [ "$in_value" -eq 1 ]; then
+          value="$buffer"
+          buffer=""
+          output="$output$key=\"$value\"\n"
+          in_value=0
+        elif [ "$in_array" -eq 1 ]; then
+          value="$buffer"
+          buffer=""
+          output="$output$arr_index=\"$value\"\n"
+          arr_index=$((arr_index + 1))
+        fi
+      else
+        buffer="$buffer$char"
+      fi
+      continue
+    fi
+
+    case "$char" in
+      "\"")
+        in_string=1
+        buffer=""
+        if [ "$in_value" -eq 0 ] && [ "$in_array" -eq 0 ]; then
+          in_key=1
+        fi
+        ;;
+      ":")
+        in_value=1
+        ;;
+      ",")
+        if [ "$in_value" -eq 1 ]; then
+          in_value=0
+        fi
+        ;;
+      "[")
+        in_array=1
+        ;;
+      "]")
+        in_array=0
+        ;;
+      "{" | "}")
+        ;;
+      *)
+        if [ "$in_value" -eq 1 ] && [ "$char" != " " ] && [ "$char" != "\n" ] && [ "$char" != "\t" ]; then
+          buffer="$buffer$char"
+        fi
+        ;;
+    esac
+  done
+
+  printf "%b" "$output"
+}
+
+extract_value() {
+  local key
+  key="$1"
+  local parsed
+  parsed="$2"
+  echo "$parsed" | grep "^$key=" | cut -d'=' -f2 | tr -d '"'
+}

test/fast/Aliases/'nvm alias' should not accept aliases with a hash

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+\. ../../../nvm.sh
+
+die () { echo "$@" ; exit 1; }
+
+OUTPUT="$(nvm alias foo#bar baz 2>&1)"
+EXPECTED_OUTPUT="Aliases with a comment delimiter (#) are not supported."
+[ "$OUTPUT" = "$EXPECTED_OUTPUT" ] || die "trying to create an alias with a hash should fail with '$EXPECTED_OUTPUT', got '$OUTPUT'"
+
+EXIT_CODE="$(nvm alias foo#bar baz >/dev/null 2>&1 ; echo $?)"
+[ "$EXIT_CODE" = "1" ] || die "trying to create an alias with a hash should fail with code 1, got '$EXIT_CODE'"
+
+OUTPUT="$(nvm alias foo# baz 2>&1)"
+EXPECTED_OUTPUT="Aliases with a comment delimiter (#) are not supported."
+[ "$OUTPUT" = "$EXPECTED_OUTPUT" ] || die "trying to create an alias ending with a hash should fail with '$EXPECTED_OUTPUT', got '$OUTPUT'"
+
+EXIT_CODE="$(nvm alias foo# baz >/dev/null 2>&1 ; echo $?)"
+[ "$EXIT_CODE" = "1" ] || die "trying to create an alias ending with a hash should fail with code 1, got '$EXIT_CODE'"
+
+OUTPUT="$(nvm alias \#bar baz 2>&1)"
+EXPECTED_OUTPUT="Aliases with a comment delimiter (#) are not supported."
+[ "$OUTPUT" = "$EXPECTED_OUTPUT" ] || die "trying to create an alias starting with a hash should fail with '$EXPECTED_OUTPUT', got '$OUTPUT'"
+
+EXIT_CODE="$(nvm alias \#bar baz >/dev/null 2>&1 ; echo $?)"
+[ "$EXIT_CODE" = "1" ] || die "trying to create an alias starting with a hash should fail with code 1, got '$EXIT_CODE'"

test/fast/Unit tests/nvm_process_nvmrc

@@ -0,0 +1,34 @@
+#!/bin/sh
+
+die () { echo "$@" ; cleanup ; exit 1; }
+
+cleanup() {
+  echo 'cleaned up'
+}
+
+\. ../../../nvm.sh
+
+\. ../../common.sh
+
+for f in ../../../test/fixtures/nvmrc/test/fixtures/valid/*; do
+  STDOUT="$(nvm_process_nvmrc $f/.nvmrc 2>/dev/null)"
+  EXIT_CODE="$(nvm_process_nvmrc $f/.nvmrc >/dev/null 2>/dev/null; echo $?)"
+
+  EXPECTED="$(extract_value node "$(parse_json "$(cat "$f/expected.json")")")"
+
+  [ "${EXIT_CODE}" = "0" ] || die "$(basename "${f}"): expected exit code of 0 but got ${EXIT_CODE}"
+
+  [ "${STDOUT}" = "${EXPECTED}" ] || die "$(basename "${f}"): expected STDOUT of \`${EXPECTED}\` but got \`${STDOUT}\`"
+done
+
+for f in ../../../test/fixtures/nvmrc/test/fixtures/invalid/*; do
+  STDOUT="$(nvm_process_nvmrc $f/.nvmrc 2>/dev/null)"
+  STDERR="$(nvm_process_nvmrc $f/.nvmrc 2>&1 >/dev/null | awk '{if(NR > 8) print $0}' | strip_colors)"
+  EXIT_CODE="$(nvm_process_nvmrc $f/.nvmrc >/dev/null 2>/dev/null; echo $?)"
+
+  EXPECTED="$(parse_json "$(cat "$f/expected.json")" | sed 's/^[0-9]*="//;s/"$//')"
+
+  [ "${EXIT_CODE}" != "0" ] || die "$(basename "${f}"): expected exit code of 'not 0' but got ${EXIT_CODE}"
+
+  [ "${STDERR}" = "${EXPECTED}" ] || die "$(basename "${f}"): expected STDERR of \`${EXPECTED}\` but got \`${STDERR}\`"
+done