ass-test-help: Remove lib/bats/helpers dependency

This helps ensure that the assertion library or test environment imports
everything it needs rather than relying on this file.

Author: mbland

lib/bats/assertion-test-helpers

@@ -30,14 +30,19 @@ if [[ -z "$ASSERTION_SOURCE" ]]; then
 fi
 
 . "$ASSERTION_SOURCE"
-. "${BASH_SOURCE%/*}/helpers"
+
+# Temp directory for assertion test artifacts.
+#
+# Defined the same as `BATS_TEST_ROOTDIR` from `lib/bats/helpers`, but not
+# dependent on it, so this file remains self-contained.
+export ASSERTION_TEST_ROOTDIR="${BATS_TEST_ROOTDIR:-$BATS_TMPDIR/test rootdir}"
 
 # This is the file written to by `printf_to_test_output_file`.
-export TEST_OUTPUT_FILE="$BATS_TEST_ROOTDIR/test-output.txt"
+export TEST_OUTPUT_FILE="$ASSERTION_TEST_ROOTDIR/test-output.txt"
 
 # Path to the script generated by `expect_assertion_*` to test whether
 # `restore_bats_shell_options` was called or not.
-readonly ASSERTION_TEST_SCRIPT="$BATS_TEST_ROOTDIR/assertion-test.bats"
+readonly ASSERTION_TEST_SCRIPT="$ASSERTION_TEST_ROOTDIR/assertion-test.bats"
 
 # Format for the error message emitted when `ASSERTION_TEST_SCRIPT` fails.
 # Should be called as:
@@ -202,8 +207,8 @@ export -f printf_with_error
 # Arguments:
 #   ...:  Arguments to `printf`
 printf_to_test_output_file() {
-  if [[ ! -d "$BATS_TEST_ROOTDIR" ]]; then
-    mkdir "$BATS_TEST_ROOTDIR"
+  if [[ ! -d "$ASSERTION_TEST_ROOTDIR" ]]; then
+    mkdir "$ASSERTION_TEST_ROOTDIR"
   fi
   printf "$@" >"$TEST_OUTPUT_FILE"
 }
@@ -270,12 +275,26 @@ __run_command_and_assertion_in_subshell() {
 # Arguments:
 #   ...: Body of the test case to execute
 __run_assertion_test_script() {
-  create_bats_test_script "${ASSERTION_TEST_SCRIPT#$BATS_TEST_ROOTDIR/}" \
-    '#! /usr/bin/env bats' \
-    "load '$ASSERTION_SOURCE'" \
-    "@test \"$BATS_TEST_DESCRIPTION\" {" \
-    "$@" \
-    '}'
+  local script_dir="${ASSERTION_TEST_SCRIPT%/*}"
+  local script_impl=('#! /usr/bin/env bats'
+    "load '$ASSERTION_SOURCE'"
+    "@test \"$BATS_TEST_DESCRIPTION\" {"
+    "$@"
+    '}')
+
+  if [[ ! -d "$script_dir" ]] && ! mkdir -p "$script_dir"; then
+    printf 'Failed to create parent directory for assertion test script: %s\n' \
+      "$ASSERTION_TEST_SCRIPT" >&2
+    return '1'
+  elif ! printf '%s\n' "${script_impl[@]}" >"$ASSERTION_TEST_SCRIPT"; then
+    printf 'Failed to create assertion test script: %s\n' \
+      "$ASSERTION_TEST_SCRIPT" >&2
+    return '1'
+  elif ! chmod 755 "$ASSERTION_TEST_SCRIPT"; then
+    printf 'Failed to set permissions for assertion test script: %s\n' \
+      "$ASSERTION_TEST_SCRIPT" >&2
+    return '1'
+  fi
   run "$ASSERTION_TEST_SCRIPT"
 }
 

tests/assertion-test-helpers.bats

@@ -17,17 +17,37 @@ setup() {
 
 teardown() {
   remove_bats_test_dirs
+  rm -rf "$BATS_TMPDIR/bin"
 }
 
 emit_debug_info() {
   printf 'STATUS: %s\nOUTPUT:\n%s\n' "$status" "$output" >&2
 }
 
+create_failing_test_stub() {
+  local cmd_name="$1"
+  local cmd_path="$BATS_TMPDIR/bin/$cmd_name"
+
+  if [[ ! -d "$BATS_TMPDIR/bin" ]]; then
+    mkdir -p "$BATS_TMPDIR/bin"
+  fi
+  printf '%s\n' 'printf "ARG: \"%s\"\n" "$@"' 'exit 1' >"$cmd_path"
+  chmod 755 "$cmd_path"
+  PATH="$BATS_TMPDIR/bin:$PATH"
+  hash "$cmd_name"
+}
+
+remove_failing_test_stub() {
+  local cmd_name="$1"
+  rm -f "$BATS_TMPDIR/bin/$cmd_name"
+  hash "$cmd_name"
+}
+
 run_assertion_test() {
   set "$DISABLE_BATS_SHELL_OPTIONS"
   setup_assertion_test "$@"
   restore_bats_shell_options
-  run "$BATS_TEST_ROOTDIR/$EXPECT_ASSERTION_TEST_SCRIPT"
+  run "$ASSERTION_TEST_ROOTDIR/$EXPECT_ASSERTION_TEST_SCRIPT"
 }
 
 setup_assertion_test() {
@@ -59,7 +79,7 @@ check_failure_output() {
 }
 
 __check_failure_output() {
-  local test_script="$BATS_TEST_ROOTDIR/$EXPECT_ASSERTION_TEST_SCRIPT"
+  local test_script="$ASSERTION_TEST_ROOTDIR/$EXPECT_ASSERTION_TEST_SCRIPT"
   local assertion_line="${ASSERTION%%$'\n'*}"
   local expected_output
   local result='0'
@@ -83,6 +103,10 @@ __check_failure_output() {
   return "$result"
 }
 
+check_matches() {
+  [[ "$1" =~ $2 ]]
+}
+
 @test "$SUITE: printf_with_error" {
   run printf_with_error 'foo bar baz'
   emit_debug_info
@@ -113,6 +137,58 @@ __check_failure_output() {
   [ "$output" == "$err_msg" ]
 }
 
+@test "$SUITE: fail to create assertion test script parent dir" {
+  create_failing_test_stub 'mkdir'
+  run __run_assertion_test_script
+  remove_failing_test_stub 'mkdir'
+
+  local expected
+  printf -v expected '%s\n' 'ARG: "-p"' "ARG: \"${ASSERTION_TEST_SCRIPT%/*}\""
+  expected+='Failed to create parent directory for assertion test script: '
+  expected+="$ASSERTION_TEST_SCRIPT"
+
+  printf 'EXPECTED OUTPUT:\n%s\n' "$expected"
+  emit_debug_info
+  [ "$status" -eq '1' ]
+  [ "$output" == "$expected" ]
+}
+
+@test "$SUITE: fail to create the assertion test script" {
+  skip_if_cannot_trigger_file_permission_failure
+  mkdir "$ASSERTION_TEST_ROOTDIR"
+  chmod ugo-w "$ASSERTION_TEST_ROOTDIR"
+  run __run_assertion_test_script
+
+  local printf_err_pattern="$_GO_CORE_DIR/lib/bats/assertion-test-helpers: "
+  printf_err_pattern+="line [1-9][0-9]*: $ASSERTION_TEST_SCRIPT: "
+  printf_err_pattern+='Permission denied'
+  printf 'EXPECTED PRINTF ERROR PATTERN:\n%s\n' "$printf_err_pattern" >&2
+
+  local err_msg="Failed to create assertion test script: $ASSERTION_TEST_SCRIPT"
+  printf 'EXPECTED FAILURE MESSAGE:\n%s\n' "$err_msg" >&2
+
+  emit_debug_info
+  [ "$status" -eq '1' ]
+  check_matches "${lines[0]}" "$printf_err_pattern"
+  [ "${lines[1]}" == "$err_msg" ]
+}
+
+@test "$SUITE: fail to set permissions for the assertion test script" {
+  create_failing_test_stub 'chmod'
+  run __run_assertion_test_script
+  remove_failing_test_stub 'chmod'
+
+  local expected
+  printf -v expected '%s\n' 'ARG: "755"' "ARG: \"$ASSERTION_TEST_SCRIPT\""
+  expected+='Failed to set permissions for assertion test script: '
+  expected+="$ASSERTION_TEST_SCRIPT"
+
+  printf 'EXPECTED OUTPUT:\n%s\n' "$expected"
+  emit_debug_info
+  [ "$status" -eq '1' ]
+  [ "$output" == "$expected" ]
+}
+
 @test "$SUITE: successful assertion" {
   run_assertion_test 'success'
   emit_debug_info