Add assert_file_empty and assert_file_not_empty

README.md

@@ -63,6 +63,44 @@ On failure, the path is displayed.
 path : /path/to/existing-file
 --
 ```
+### `assert_file_empty`
+
+Fail if the given file or directory is not empty.
+
+```bash
+@test 'assert_file_empty()' {
+  assert_file_empty /path/to/empty-file
+}
+```
+
+On failure, the path and the content of the file is displayed.
+
+```
+-- file is not empty --
+path : /path/to/empty-file
+output (2 lines) : content-line-1
+content-line-2
+--
+```
+
+
+### `assert_file_not_empty`
+
+Fail if the given file or directory empty.
+
+```bash
+@test 'assert_file_not_empty() {
+  assert_file_not_empty /path/to/non-empty-file
+}
+```
+
+On failure, the path is displayed.
+
+```
+-- file empty, but it was expected to contain something --
+path : /path/to/non-empty-file
+--
+```
 
 
 ## Working with temporary directories

src/file.bash

@@ -72,3 +72,54 @@ assert_file_not_exist() {
       | fail
   fi
 }
+
+# Fail and display path of the file (or directory) if it is not empty.
+# This function is the logical complement of `assert_file_not_empty'.
+#
+# Globals:
+#   BATSLIB_FILE_PATH_REM
+#   BATSLIB_FILE_PATH_ADD
+# Arguments:
+#   $1 - path
+# Returns:
+#   0 - file empty
+#   1 - otherwise
+# Outputs:
+#   STDERR - details, on failure
+assert_file_empty() {
+  local -r file="$1"
+  if [[ -s "$file" ]]; then
+    local -r rem="$BATSLIB_FILE_PATH_REM"
+    local -r add="$BATSLIB_FILE_PATH_ADD"
+    { local -ir width=8
+      batslib_print_kv_single "$width" 'path' "${file/$rem/$add}"
+      batslib_print_kv_single_or_multi "$width" \
+          'output' "$(cat $file)"
+    } | batslib_decorate 'file is not empty' \
+      | fail
+  fi
+}
+
+# Fail and display path of the file (or directory) if it is empty. This
+# function is the logical complement of `assert_file_empty'.
+#
+# Globals:
+#   BATSLIB_FILE_PATH_REM
+#   BATSLIB_FILE_PATH_ADD
+# Arguments:
+#   $1 - path
+# Returns:
+#   0 - file is not empty
+#   1 - otherwise
+# Outputs:
+#   STDERR - details, on failure
+assert_file_not_empty() {
+  local -r file="$1"
+  if [[ ! -s "$file" ]]; then
+    local -r rem="$BATSLIB_FILE_PATH_REM"
+    local -r add="$BATSLIB_FILE_PATH_ADD"
+    batslib_print_kv_single 4 'path' "${file/$rem/$add}" \
+      | batslib_decorate 'file empty, but it was expected to contain something' \
+      | fail
+  fi
+}

test/52-assert-10-assert_file_empty.bats

@@ -0,0 +1,61 @@
+#!/usr/bin/env bats
+
+load 'test_helper'
+fixtures 'empty'
+
+# Correctness
+@test 'assert_file_empty() <file>: returns 0 if <file> empty' {
+  local -r file="${TEST_FIXTURE_ROOT}/dir/empty-file"
+  run assert_file_empty "$file"
+  [ "$status" -eq 0 ]
+  [ "${#lines[@]}" -eq 0 ]
+}
+
+@test 'assert_file_empty() <file>: returns 1 and displays content if <file> is not empty' {
+  local -r file="${TEST_FIXTURE_ROOT}/dir/non-empty-file"
+  run assert_file_empty "$file"
+  [ "$status" -eq 1 ]
+  [ "${#lines[@]}" -eq 4 ]
+  [ "${lines[0]}" == '-- file is not empty --' ]
+  [ "${lines[1]}" == "path     : ${TEST_FIXTURE_ROOT}/dir/non-empty-file" ]
+  [ "${lines[2]}" == 'output   : Not empty' ]
+  [ "${lines[3]}" == '--' ]
+}
+
+# Transforming path
+@test 'assert_file_empty() <file>: replace prefix of displayed path' {
+  local -r BATSLIB_FILE_PATH_REM="#${TEST_FIXTURE_ROOT}"
+  local -r BATSLIB_FILE_PATH_ADD='..'
+  run assert_file_empty "${TEST_FIXTURE_ROOT}/dir/non-empty-file"
+  [ "$status" -eq 1 ]
+  [ "${#lines[@]}" -eq 4 ]
+  [ "${lines[0]}" == '-- file is not empty --' ]
+  [ "${lines[1]}" == "path     : ../dir/non-empty-file" ]
+  [ "${lines[2]}" == 'output   : Not empty' ]
+  [ "${lines[3]}" == '--' ]
+}
+
+@test 'assert_file_empty() <file>: replace suffix of displayed path' {
+  local -r BATSLIB_FILE_PATH_REM='%non-empty-file'
+  local -r BATSLIB_FILE_PATH_ADD='..'
+  run assert_file_empty "${TEST_FIXTURE_ROOT}/dir/non-empty-file"
+  [ "$status" -eq 1 ]
+  [ "${#lines[@]}" -eq 4 ]
+  [ "${lines[0]}" == '-- file is not empty --' ]
+  [ "${lines[1]}" == "path     : ${TEST_FIXTURE_ROOT}/dir/.." ]
+  [ "${lines[2]}" == 'output   : Not empty' ]
+  [ "${lines[3]}" == '--' ]
+}
+
+@test 'assert_file_empty() <file>: replace infix of displayed path' {
+  local -r BATSLIB_FILE_PATH_REM='dir'
+  local -r BATSLIB_FILE_PATH_ADD='..'
+  run assert_file_empty "${TEST_FIXTURE_ROOT}/dir/non-empty-file"
+  [ "$status" -eq 1 ]
+  [ "${#lines[@]}" -eq 4 ]
+  [ "${lines[0]}" == '-- file is not empty --' ]
+  [ "${lines[1]}" == "path     : ${TEST_FIXTURE_ROOT}/../non-empty-file" ]
+  [ "${lines[2]}" == 'output   : Not empty' ]
+  [ "${lines[3]}" == '--' ]
+}
+

test/52-assert-11-assert_file_not_empty.bats

@@ -0,0 +1,58 @@
+#!/usr/bin/env bats
+
+load 'test_helper'
+fixtures 'empty'
+
+# Correctness
+@test 'assert_file_not_empty() <file>: returns 0 if <file> is not empty' {
+  local -r file="${TEST_FIXTURE_ROOT}/dir/non-empty-file"
+  run assert_file_not_empty "$file"
+  [ "$status" -eq 0 ]
+  [ "${#lines[@]}" -eq 0 ]
+}
+
+@test 'assert_file_not_empty() <file>: returns 1 and displays path if <file> emptys' {
+  local -r file="${TEST_FIXTURE_ROOT}/dir/empty-file"
+  run assert_file_not_empty "$file"
+  [ "$status" -eq 1 ]
+  [ "${#lines[@]}" -eq 3 ]
+  [ "${lines[0]}" == '-- file empty, but it was expected to contain something --' ]
+  [ "${lines[1]}" == "path : $file" ]
+  [ "${lines[2]}" == '--' ]
+}
+
+# Transforming path
+@test 'assert_file_not_empty() <file>: replace prefix of displayed path' {
+  local -r BATSLIB_FILE_PATH_REM="#${TEST_FIXTURE_ROOT}"
+  local -r BATSLIB_FILE_PATH_ADD='..'
+  run assert_file_not_empty "${TEST_FIXTURE_ROOT}/dir/empty-file"
+  [ "$status" -eq 1 ]
+  [ "${#lines[@]}" -eq 3 ]
+  [ "${lines[0]}" == '-- file empty, but it was expected to contain something --' ]
+  [ "${lines[1]}" == "path : ../dir/empty-file" ]
+  [ "${lines[2]}" == '--' ]
+}
+
+@test 'assert_file_not_empty() <file>: replace suffix of displayed path' {
+  local -r BATSLIB_FILE_PATH_REM='%empty-file'
+  local -r BATSLIB_FILE_PATH_ADD='..'
+  run assert_file_not_empty "${TEST_FIXTURE_ROOT}/dir/empty-file"
+  [ "$status" -eq 1 ]
+  [ "${#lines[@]}" -eq 3 ]
+  [ "${lines[0]}" == '-- file empty, but it was expected to contain something --' ]
+echo  [ "${lines[1]}" == "path : ${TEST_FIXTURE_ROOT}/dir/.." ]
+  [ "${lines[1]}" == "path : ${TEST_FIXTURE_ROOT}/dir/.." ]
+  [ "${lines[2]}" == '--' ]
+}
+
+@test 'assert_file_not_empty() <file>: replace infix of displayed path' {
+  local -r BATSLIB_FILE_PATH_REM='dir'
+  local -r BATSLIB_FILE_PATH_ADD='..'
+  run assert_file_not_empty "${TEST_FIXTURE_ROOT}/dir/empty-file"
+  [ "$status" -eq 1 ]
+  [ "${#lines[@]}" -eq 3 ]
+  [ "${lines[0]}" == '-- file empty, but it was expected to contain something --' ]
+  [ "${lines[1]}" == "path : ${TEST_FIXTURE_ROOT}/../empty-file" ]
+  [ "${lines[2]}" == '--' ]
+}
+

test/fixtures/empty/dir/non-empty-file

@@ -0,0 +1 @@
+Not empty