use bats-assert instead of embedded helpers

Author: jasonkarns

package-lock.json

@@ -37,6 +37,7 @@
   "devDependencies": {
     "@nodenv/nodenv": "^1.1.2",
     "bats": "^0.4.2",
+    "bats-assert": "^1.1.1",
     "brew-publish": "^2.3.1"
   },
   "dependencies": {

package.json

@@ -1,5 +1,4 @@
 #!/usr/bin/env bats
-# Tests of basic usage and functionality
 
 load test_helper
 

test/nodenv-package-json-engine.bats

@@ -1,10 +1,12 @@
 # shellcheck shell=bash
 
-unset NODENV_VERSION
-
-EXAMPLE_PACKAGE_DIR="$BATS_TMPDIR/example_package"
+load ../node_modules/bats-assert/all
 
 setup() {
+  unset NODENV_VERSION
+
+  EXAMPLE_PACKAGE_DIR="$BATS_TMPDIR/example_package"
+
   export NODENV_ROOT="$BATS_TMPDIR/nodenv_root"
 
   PATH="$(npm bin):/usr/bin:/bin:/usr/sbin:/sbin"
@@ -19,38 +21,6 @@ teardown() {
   rm -r "$NODENV_ROOT"
 }
 
-assert() {
-  if ! "$@"; then
-    flunk "failed: $*"
-  fi
-}
-
-assert_equal() {
-  if [ "$1" != "$2" ]; then
-    { echo "expected: $1"
-      echo "actual:   $2"
-    } | flunk
-  fi
-}
-
-assert_output() {
-  local expected
-  if [ $# -eq 0 ]; then expected="$(cat -)"
-  else expected="$1"
-  fi
-  # shellcheck disable=SC2154
-  assert_equal "$expected" "$output"
-}
-
-assert_success() {
-  # shellcheck disable=SC2154
-  if [ "$status" -ne 0 ]; then
-    flunk "command failed with exit status $status"
-  elif [ "$#" -gt 0 ]; then
-    assert_output "$1"
-  fi
-}
-
 # cd_into_package nodeVersion [extraArgs]
 cd_into_package() {
   mkdir -p "$EXAMPLE_PACKAGE_DIR"
@@ -87,11 +57,3 @@ create_version() {
   mkdir -p "$d"
   ln -s /bin/echo "$d/node"
 }
-
-flunk() {
-  { if [ "$#" -eq 0 ]; then cat -
-    else echo "$@"
-    fi
-  } >&2
-  return 1
-}