aliases-circular: steal test helper from rbenv and use it

test/bats/aliases-circular.bats

@@ -1,5 +1,7 @@
 #!/usr/bin/env bats
 
+load test_helper
+
 NVM_SRC_DIR="${BATS_TEST_DIRNAME}/../.."
 
 setup() {
@@ -30,35 +32,27 @@ teardown() {
     die () { echo $@ ; exit 1; }
 
     run nvm_resolve_alias loopback
-    [ "$output" -eq "∞" ]
-
+    assert_success "∞"
     run nvm alias loopback
-    [ "$output" -eq "loopback -> loopback (-> ∞)" ]
+    assert_success "loopback -> loopback (-> ∞)"
 
-    ALIAS="$(nvm_resolve_alias one)"
-    [ "_$ALIAS" = "_∞" ]
-    OUTPUT="$(nvm alias one)"
-    EXPECTED_OUTPUT="one -> two (-> ∞)"
-    [ "_$OUTPUT" = "_$EXPECTED_OUTPUT" ]
+    run nvm_resolve_alias one
+    assert_success "∞"
+    run nvm alias one
+    assert_success "one -> two (-> ∞)"
 
-    ALIAS="$(nvm_resolve_alias two)"
-    [ "_$ALIAS" = "_∞" ]
-    OUTPUT="$(nvm alias two)"
-    EXPECTED_OUTPUT="two -> three (-> ∞)"
-    [ "_$OUTPUT" = "_$EXPECTED_OUTPUT" ]
+    run nvm_resolve_alias two
+    assert_success "∞"
+    run nvm alias two
+    assert_success "two -> three (-> ∞)"
 
-    ALIAS="$(nvm_resolve_alias three)"
-    [ "_$ALIAS" = "_∞" ]
-    OUTPUT="$(nvm alias three)"
-    EXPECTED_OUTPUT="three -> one (-> ∞)"
-    [ "_$OUTPUT" = "_$EXPECTED_OUTPUT" ]
+    run nvm_resolve_alias three
+    assert_success "∞"
+    run nvm alias three
+    assert_success "three -> one (-> ∞)"
 
-    ALIAS="$(nvm_resolve_alias four)"
-    [ "_$ALIAS" = "_∞" ]
-    OUTPUT="$(nvm alias four)"
-    EXPECTED_OUTPUT="four -> two (-> ∞)"
-    [ "_$OUTPUT" = "_$EXPECTED_OUTPUT" ]
-
-    true
+    run nvm_resolve_alias four
+    assert_success "∞"
+    run nvm alias four
+    assert_success "four -> two (-> ∞)"
 }
-

test/bats/test_helper.bash

@@ -0,0 +1,127 @@
+# test_helper.bash stolen from rbenv
+#
+#unset RBENV_VERSION
+#unset RBENV_DIR
+
+if enable -f "${BATS_TEST_DIRNAME}"/../libexec/rbenv-realpath.dylib realpath 2>/dev/null; then
+  RBENV_TEST_DIR="$(realpath "$BATS_TMPDIR")/rbenv"
+else
+  if [ -n "$RBENV_NATIVE_EXT" ]; then
+    echo "rbenv: failed to load \`realpath' builtin" >&2
+    exit 1
+  fi
+  RBENV_TEST_DIR="${BATS_TMPDIR}/rbenv"
+fi
+
+# guard against executing this block twice due to bats internals
+if [ "$RBENV_ROOT" != "${RBENV_TEST_DIR}/root" ]; then
+  export RBENV_ROOT="${RBENV_TEST_DIR}/root"
+  export HOME="${RBENV_TEST_DIR}/home"
+
+  PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin
+  PATH="${RBENV_TEST_DIR}/bin:$PATH"
+  PATH="${BATS_TEST_DIRNAME}/../libexec:$PATH"
+  PATH="${BATS_TEST_DIRNAME}/libexec:$PATH"
+  PATH="${RBENV_ROOT}/shims:$PATH"
+  export PATH
+fi
+
+teardown() {
+  rm -rf "$RBENV_TEST_DIR"
+}
+
+flunk() {
+  { if [ "$#" -eq 0 ]; then cat -
+    else echo "$@"
+    fi
+  } | sed "s:${RBENV_TEST_DIR}:TEST_DIR:g" >&2
+  return 1
+}
+
+assert_success() {
+  if [ "$status" -ne 0 ]; then
+    flunk "command failed with exit status $status"
+  elif [ "$#" -gt 0 ]; then
+    assert_output "$1"
+  fi
+}
+
+assert_failure() {
+  if [ "$status" -eq 0 ]; then
+    flunk "expected failed exit status"
+  elif [ "$#" -gt 0 ]; then
+    assert_output "$1"
+  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="$1"
+  fi
+  assert_equal "$expected" "$output"
+}
+
+assert_line() {
+  if [ "$1" -ge 0 ] 2>/dev/null; then
+    assert_equal "$2" "${lines[$1]}"
+  else
+    local line
+    for line in "${lines[@]}"; do
+      if [ "$line" = "$1" ]; then return 0; fi
+    done
+    flunk "expected line \`$1'"
+  fi
+}
+
+refute_line() {
+  if [ "$1" -ge 0 ] 2>/dev/null; then
+    local num_lines="${#lines[@]}"
+    if [ "$1" -lt "$num_lines" ]; then
+      flunk "output has $num_lines lines"
+    fi
+  else
+    local line
+    for line in "${lines[@]}"; do
+      if [ "$line" = "$1" ]; then
+        flunk "expected to not find line \`$line'"
+      fi
+    done
+  fi
+}
+
+assert() {
+  if ! "$@"; then
+    flunk "failed: $@"
+  fi
+}
+
+# Output a modified PATH that ensures that the given executable is not present,
+# but in which system utils necessary for rbenv operation are still available.
+path_without() {
+  local exe="$1"
+  local path="${PATH}:"
+  local found alt util
+  for found in $(which -a "$exe"); do
+    found="${found%/*}"
+    if [ "$found" != "${RBENV_ROOT}/shims" ]; then
+      alt="${RBENV_TEST_DIR}/$(echo "${found#/}" | tr '/' '-')"
+      mkdir -p "$alt"
+      for util in bash head cut readlink greadlink; do
+        if [ -x "${found}/$util" ]; then
+          ln -s "${found}/$util" "${alt}/$util"
+        fi
+      done
+      path="${path/${found}:/${alt}:}"
+    fi
+  done
+  echo "${path%:}"
+}