Add exists, is_file, is_dir, is_link and is_readable assertion methods

Also includes documentation and tests for the above

README.md

@@ -124,7 +124,47 @@ assert 'a' in 'a' 'b' 'c'
 Asserts that a value is not included in the comparison array.
 
 ```sh
-asserts 'a' not_in 'x' 'y' 'z'
+assert 'a' not_in 'x' 'y' 'z'
+```
+
+#### exists
+
+Asserts that the given path exists
+
+```sh
+assert /path/to/file exists
+```
+
+#### is_file
+
+Asserts that the given path exists and is a file
+
+```sh
+assert /path/to/file is_file
+```
+
+#### is_dir
+
+Asserts that the given path exists and is a directory
+
+```sh
+assert /path/to/dir is_dir
+```
+
+#### is_link
+
+Asserts that the given path exists and is a symbolic link
+
+```sh
+assert /path/to/link is_link
+```
+
+#### is_readable
+
+Asserts that the given path exists and is a symbolic readable
+
+```sh
+assert /path/to/file is_readable
 ```
 
 ### Loading scripts

tests/_support/assertions.zunit.link

@@ -0,0 +1 @@
+../assertions.zunit

tests/assertions.zunit

@@ -135,3 +135,70 @@
   assert "$state" equals 1
   assert "$output" same_as "'a' is in (a ; b ; c)"
 }
+
+@test 'Test _zunit_assert_exists success' {
+  run assert './assertions.zunit' exists
+  assert "$state" equals 0
+  assert "$output" is_empty
+}
+
+@test 'Test _zunit_assert_exists failure' {
+  run assert './non-existent-file' exists
+  assert "$state" equals 1
+  assert "$output" same_as "'./non-existent-file' does not exist"
+}
+
+@test 'Test _zunit_assert_is_file success' {
+  run assert './assertions.zunit' is_file
+  assert "$state" equals 0
+  assert "$output" is_empty
+}
+
+@test 'Test _zunit_assert_is_file failure' {
+  run assert './_support' is_file
+  assert "$state" equals 1
+  assert "$output" same_as "'./_support' does not exist or is not a file"
+}
+
+@test 'Test _zunit_assert_is_dir success' {
+  run assert './_support' is_dir
+  assert "$state" equals 0
+  assert "$output" is_empty
+}
+
+@test 'Test _zunit_assert_is_dir failure' {
+  run assert './assertions.zunit' is_dir
+  assert "$state" equals 1
+  assert "$output" same_as "'./assertions.zunit' does not exist or is not a directory"
+}
+
+@test 'Test _zunit_assert_is_link success' {
+  run assert './_support/assertions.zunit.link' is_link
+  assert "$state" equals 0
+  assert "$output" is_empty
+}
+
+@test 'Test _zunit_assert_is_link failure' {
+  run assert './assertions.zunit' is_link
+  assert "$state" equals 1
+  assert "$output" same_as "'./assertions.zunit' does not exist or is not a symbolic link"
+}
+
+@test 'Test _zunit_assert_is_readable success' {
+  run assert './assertions.zunit' is_readable
+  assert "$state" equals 0
+  assert "$output" is_empty
+}
+
+@test 'Test _zunit_assert_is_readable failure' {
+  # Make file unreadable before checking it
+  chmod 000 "$testdir/_support/non-readable-file"
+
+  run assert './_support/non-readable-file' is_readable
+
+  # Change permissions back before the test makes its assertions
+  chmod 644 "$testdir/_support/non-readable-file"
+
+  assert "$state" equals 1
+  assert "$output" same_as "'./_support/non-readable-file' does not exist or is not readable"
+}

zunit

@@ -132,6 +132,91 @@ function _zunit_assert_not_in() {
   exit 1
 }
 
+###
+# Assert the a path exists
+###
+function _zunit_assert_exists() {
+  local path=$1
+
+  # If filepath is relative, prepend the test directory
+  if [[ "${path:0:1}" != "/" ]]; then
+    filepath="$testdir/${path}"
+  fi
+
+  [[ -e $filepath ]] && return 0
+
+  echo "'$path' does not exist"
+  exit 1
+}
+
+###
+# Assert the a path exists and is a file
+###
+function _zunit_assert_is_file() {
+  local path=$1
+
+  # If filepath is relative, prepend the test directory
+  if [[ "${path:0:1}" != "/" ]]; then
+    filepath="$testdir/${path}"
+  fi
+
+  [[ -f $filepath ]] && return 0
+
+  echo "'$path' does not exist or is not a file"
+  exit 1
+}
+
+###
+# Assert the a path exists and is a directory
+###
+function _zunit_assert_is_dir() {
+  local path=$1
+
+  # If filepath is relative, prepend the test directory
+  if [[ "${path:0:1}" != "/" ]]; then
+    filepath="$testdir/${path}"
+  fi
+
+  [[ -d $filepath ]] && return 0
+
+  echo "'$path' does not exist or is not a directory"
+  exit 1
+}
+
+###
+# Assert the a path exists and is a symbolic link
+###
+function _zunit_assert_is_link() {
+  local path=$1
+
+  # If filepath is relative, prepend the test directory
+  if [[ "${path:0:1}" != "/" ]]; then
+    filepath="$testdir/${path}"
+  fi
+
+  [[ -h $filepath ]] && return 0
+
+  echo "'$path' does not exist or is not a symbolic link"
+  exit 1
+}
+
+###
+# Assert the a path exists and is readable
+###
+function _zunit_assert_is_readable() {
+  local path=$1
+
+  # If filepath is relative, prepend the test directory
+  if [[ "${path:0:1}" != "/" ]]; then
+    filepath="$testdir/${path}"
+  fi
+
+  [[ -r $filepath ]] && return 0
+
+  echo "'$path' does not exist or is not readable"
+  exit 1
+}
+
 ################################
 # Helpers for use within tests #
 ################################