diff --git a/tests.d/1003-lib-string/00.tests.sh b/tests.d/1003-lib-string/00.tests.sh
index 38d161e..23646ec 100644
--- a/tests.d/1003-lib-string/00.tests.sh
+++ b/tests.d/1003-lib-string/00.tests.sh
@@ -28,6 +28,10 @@ function testString::bumpSemanticVersion() {
   echo "→ bumping 1.2.3-alpha patch false"
   string::bumpSemanticVersion "1.2.156-alpha" "patch" "false" && echo "${RETURNED_VALUE}"
 
+  echo
+  echo "→ bumping aze patch false"
+  (string::bumpSemanticVersion "aze" "patch" "false") || echo "Failed as expected"
+
   test::endTest "Testing string::bumpSemanticVersion" 0
 }
 
@@ -220,6 +224,31 @@ function testString::trim() {
   test::endTest "Testing string::trim function" 0
 }
 
+function testString::compareSemanticVersion() {
+  echo "→ string::compareSemanticVersion '1.2.3' '1.2.3'"
+  string::compareSemanticVersion '1.2.3' '1.2.3' && echo "0=${RETURNED_VALUE}"
+  echo
+  echo "→ string::compareSemanticVersion '1.2.3-alpha' '1.2.4+az123'"
+  string::compareSemanticVersion '1.2.3-alpha' '1.2.4+az123' && echo "-1=${RETURNED_VALUE}"
+  echo
+  echo "→ string::compareSemanticVersion '1.2.3' '1.2.2'"
+  string::compareSemanticVersion '1.2.3' '1.2.2' && echo "1=${RETURNED_VALUE}"
+  echo
+  echo "→ string::compareSemanticVersion '2.2.3' '1.2.3-alpha'"
+  string::compareSemanticVersion '2.2.3' '1.2.3-alpha' && echo "1=${RETURNED_VALUE}"
+  echo
+  echo "→ string::compareSemanticVersion '1.2.3+a1212' '1.3.3'"
+  string::compareSemanticVersion '1.2.3+a1212' '1.3.3' && echo "-1=${RETURNED_VALUE}"
+  echo
+  echo "→ string::compareSemanticVersion '1.2.3-alpha+a123123' '1.2.3-alpha+123zer'"
+  string::compareSemanticVersion '1.2.3-alpha+a123123' '1.2.3-alpha+123zer' && echo "0=${RETURNED_VALUE}"
+  echo
+  echo "→ string::compareSemanticVersion '1.2a.3' '1.2.3derp'"
+  (string::compareSemanticVersion '1.2a.3' '1.2.3derp') || echo "Failed as expected"
+
+  test::endTest "Testing string::compareSemanticVersion function" 0
+}
+
 function main() {
   testString::bumpSemanticVersion
   testString::kebabCaseToSnakeCase
@@ -233,6 +262,7 @@ function main() {
   testString::split
   testString::regexGetFirst
   testString::trim
+  testString::compareSemanticVersion
 }
 
 main
\ No newline at end of file
diff --git a/tests.d/1003-lib-string/results.approved.md b/tests.d/1003-lib-string/results.approved.md
index 0957e4e..5d481a9 100644
--- a/tests.d/1003-lib-string/results.approved.md
+++ b/tests.d/1003-lib-string/results.approved.md
@@ -26,6 +26,15 @@ Exit code: `0`
 
 → bumping 1.2.3-alpha patch false
 1.2.157-alpha
+
+→ bumping aze patch false
+Failed as expected
+```
+
+**Error** output:
+
+```log
+ERROR    Failed to bump the version ⌜aze⌝ because it is not valid semantic version.
 ```
 
 ### Testing string::kebabCaseToSnakeCase
@@ -238,3 +247,38 @@ hello=⌜hello⌝
 hello=⌜hello⌝
 ```
 
+### Testing string::compareSemanticVersion function
+
+Exit code: `0`
+
+**Standard** output:
+
+```plaintext
+→ string::compareSemanticVersion '1.2.3' '1.2.3'
+0=0
+
+→ string::compareSemanticVersion '1.2.3-alpha' '1.2.4+az123'
+-1=-1
+
+→ string::compareSemanticVersion '1.2.3' '1.2.2'
+1=1
+
+→ string::compareSemanticVersion '2.2.3' '1.2.3-alpha'
+1=1
+
+→ string::compareSemanticVersion '1.2.3+a1212' '1.3.3'
+-1=-1
+
+→ string::compareSemanticVersion '1.2.3-alpha+a123123' '1.2.3-alpha+123zer'
+0=0
+
+→ string::compareSemanticVersion '1.2a.3' '1.2.3derp'
+Failed as expected
+```
+
+**Error** output:
+
+```log
+ERROR    Failed to compare versions ⌜1.2a.3⌝ and ⌜1.2.3derp⌝ because they are not valid semantic versions.
+```
+
diff --git a/tests.d/1101-self-build-utils/results.approved.md b/tests.d/1101-self-build-utils/results.approved.md
index f2c0ffe..320ac0c 100644
--- a/tests.d/1101-self-build-utils/results.approved.md
+++ b/tests.d/1101-self-build-utils/results.approved.md
@@ -129,7 +129,7 @@ CMD_ARGUMENTS_NAME_func=0 "arg1" 1 "arg2" 2 "arg3"
 CMD_COMMAND_func='cmd'
 CMD_DESCRIPTION_func=$'A long description.\n\nIn a multi-line string.\n\nWith 3 paragraphs.'
 CMD_EXAMPLES_DESCRIPTION_func=0 $'Call command with option1, option2 and some arguments.\n'
-CMD_EXAMPLES_NAME_func=0 "command -o -2 value1 arg1 more1 more2"
+CMD_EXAMPLES_NAME_func=0 "valet command -o -2 value1 arg1 more1 more2"
 CMD_FILETOSOURCE_func='source'
 CMD_FUNCTION_NAME_cmd='func'
 CMD_MAX_COMMAND_WIDTH='3'
diff --git a/tests.d/1102-self-build/results.approved.md b/tests.d/1102-self-build/results.approved.md
index c2a063a..15dcd38 100644
--- a/tests.d/1102-self-build/results.approved.md
+++ b/tests.d/1102-self-build/results.approved.md
@@ -73,9 +73,9 @@ CMD_DESCRIPTION_this=$'Valet helps you browse, understand and execute your custo
 CMD_EXAMPLES_DESCRIPTION_selfMock2=0 $'Call command1 with option1, option2 and some arguments.\n'
 CMD_EXAMPLES_DESCRIPTION_showCommandHelp=0 "Shows the help for the command cmd" 1 "Shows the help for the sub command ⌜subCmd⌝ of the command ⌜cmd⌝" 2 $'Shows the help for the program without any color and with a maximum of 50 columns\n'
 CMD_EXAMPLES_DESCRIPTION_this=0 "Displays this help text." 1 $'Active ⌜verbose⌝ mode and run the command ⌜a-command⌝ with the sub command ⌜and-sub-command⌝.\n'
-CMD_EXAMPLES_NAME_selfMock2=0 "self mock2 -o -2 value1 arg1 more1 more2"
-CMD_EXAMPLES_NAME_showCommandHelp=0 "help cmd" 1 "help cmd subCmd" 2 "help --no-colors --columns 50"
-CMD_EXAMPLES_NAME_this=0 "--help" 1 "-v a-command and-sub-command"
+CMD_EXAMPLES_NAME_selfMock2=0 "valet self mock2 -o -2 value1 arg1 more1 more2"
+CMD_EXAMPLES_NAME_showCommandHelp=0 "valet help cmd" 1 "valet help cmd subCmd" 2 "valet help --no-colors --columns 50"
+CMD_EXAMPLES_NAME_this=0 "valet --help" 1 "valet -v a-command and-sub-command"
 CMD_FILETOSOURCE_selfBuild='valet.d/commands.d/self-build.sh'
 CMD_FILETOSOURCE_selfConfig='valet.d/commands.d/self-config.sh'
 CMD_FILETOSOURCE_selfExport='valet.d/commands.d/self-export.sh'
diff --git a/tests.d/1103-self-release/results.approved.md b/tests.d/1103-self-release/results.approved.md
index d1d7819..cf6ef23 100644
--- a/tests.d/1103-self-release/results.approved.md
+++ b/tests.d/1103-self-release/results.approved.md
@@ -18,7 +18,7 @@ Exit code: `0`
 INFO     Dry run mode is enabled, no changes will be made.
 ▶ called io::invoke git rev-parse HEAD
 INFO     The current version of valet is: 1.2.3.
-INFO     Found 98 functions with documentation.
+INFO     Found 100 functions with documentation.
 ▶ called io::invoke git tag --sort=version:refname --no-color
 INFO     The last tag is: v1.2.3.
 ▶ called io::invoke git log --pretty=format:%s v1.2.3..HEAD
@@ -154,11 +154,13 @@ DEBUG    Found function: ⌜io::countArgs⌝
 DEBUG    Found function: ⌜io::listPaths⌝
 DEBUG    Found function: ⌜io::listFiles⌝
 DEBUG    Found function: ⌜io::listDirectories⌝
+DEBUG    Found function: ⌜io::isDirectoryWritable⌝
 DEBUG    Found function: ⌜kurl::toFile⌝
 DEBUG    Found function: ⌜kurl::toVar⌝
 DEBUG    Found function: ⌜profiler::enable⌝
 DEBUG    Found function: ⌜profiler::disable⌝
 DEBUG    Found function: ⌜string::cutField⌝
+DEBUG    Found function: ⌜string::compareSemanticVersion⌝
 DEBUG    Found function: ⌜string::bumpSemanticVersion⌝
 DEBUG    Found function: ⌜string::camelCaseToSnakeCase⌝
 DEBUG    Found function: ⌜string::kebabCaseToSnakeCase⌝
@@ -176,7 +178,7 @@ DEBUG    Found function: ⌜system::date⌝
 DEBUG    Found function: ⌜system::getUndeclaredVariables⌝
 DEBUG    Found function: ⌜test::commentTest⌝
 DEBUG    Found function: ⌜test::endTest⌝
-INFO     Found 98 functions with documentation.
+INFO     Found 100 functions with documentation.
 ▶ called io::invoke rm -f $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/array.md
 ▶ called io::invoke rm -f $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/codes.md
 ▶ called io::invoke rm -f $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/core.md
@@ -295,6 +297,8 @@ INFO     Found 98 functions with documentation.
 ▶ called io::writeToFile $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/string.md
 ▶ called io::writeToFileFromRef $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/core.md
 ▶ called io::writeToFile $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/core.md
+▶ called io::writeToFileFromRef $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/io.md
+▶ called io::writeToFile $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/io.md
 ▶ called io::writeToFileFromRef $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/system.md
 ▶ called io::writeToFile $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/system.md
 ▶ called io::writeToFileFromRef $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/io.md
@@ -379,6 +383,8 @@ INFO     Found 98 functions with documentation.
 ▶ called io::writeToFile $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/core.md
 ▶ called io::writeToFileFromRef $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/io.md
 ▶ called io::writeToFile $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/io.md
+▶ called io::writeToFileFromRef $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/string.md
+▶ called io::writeToFile $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/string.md
 ▶ called io::writeToFileFromRef $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/log.md
 ▶ called io::writeToFile $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/log.md
 ▶ called io::writeToFileFromRef $GLOBAL_VALET_HOME/docs/content/docs/300.libraries/io.md
diff --git a/tests.d/1300-valet-cli/results.approved.md b/tests.d/1300-valet-cli/results.approved.md
index 90117e0..2eb935f 100644
--- a/tests.d/1300-valet-cli/results.approved.md
+++ b/tests.d/1300-valet-cli/results.approved.md
@@ -76,7 +76,7 @@ ARGUMENTS
 
 EXAMPLES
 
-  self mock2 -o -2 value1 arg1 more1 more2
+  valet self mock2 -o -2 value1 arg1 more1 more2
       Call command1 with option1, option2 and some arguments.
       
 
@@ -235,12 +235,12 @@ ARGUMENTS
 
 EXAMPLES
 
-  help cmd
+  valet help cmd
       Shows the help for the command ⌜cmd⌝
-  help cmd subCmd
+  valet help cmd subCmd
       Shows the help for the sub command 
       ⌜subCmd⌝ of the command ⌜cmd⌝
-  help --no-colors --columns 50
+  valet help --no-colors --columns 50
       Shows the help for the program without any
       color and with a maximum of 50 columns
       
@@ -1144,7 +1144,7 @@ COMMANDS
   self test
       Test your valet custom commands.
   self update
-      Update valet using the latest release on GitHub.
+      Install or update valet using the latest release on GitHub.
 
 ```
 
diff --git a/valet.d/lib-io b/valet.d/lib-io
index 51b8926..f374b1f 100644
--- a/valet.d/lib-io
+++ b/valet.d/lib-io
@@ -844,13 +844,9 @@ function io::listDirectories() {
 # fi
 # ```
 function io::isDirectoryWritable() {
-  path="${1:-}/writable-test"
-  if (: >"${path}") &>/dev/null; then
-    if ! rm "${path}" 1>/dev/null; then
-      return 1
-    fi
-    return 0
-  else
+  local path="${1:-}/writable-test-${BASHPID}"
+  if ! (: >"${path}") &>/dev/null || ! rm "${path}" 1>/dev/null; then
     return 1
   fi
+  return 0
 }
\ No newline at end of file
diff --git a/valet.d/lib-string b/valet.d/lib-string
index 10b050e..d532e0d 100644
--- a/valet.d/lib-string
+++ b/valet.d/lib-string
@@ -48,6 +48,55 @@ function string::cutField() {
   RETURNED_VALUE=""
 }
 
+# ## string::compareSemanticVersion
+#
+# This function allows to compare two semantic versions formatted like:
+# major.minor.patch-prerelease+build
+#
+# - $1: **version1** _as string_:
+#       the first version to compare
+# - $2: **version2** _as string_:
+#       the second version to compare
+#
+# Returns:
+#
+# - `RETURNED_VALUE`:
+#   - 0 if the versions are equal,
+#   - 1 if version1 is greater,
+#   - -1 if version2 is greater
+#
+# ```bash
+# string::compareSemanticVersion "2.3.4-prerelease+build" "1.2.3-prerelease+build"
+# local comparison="${RETURNED_VALUE}"
+# ```
+#
+# > The prerelease and build are ignored in the comparison.
+function string::compareSemanticVersion() {
+  local version1="${1#v}"
+  local version2="${2#v}"
+
+  local -i semVerIndex
+  local semVerNumber1 semVerNumber2
+  for semVerIndex in {0..2}; do
+    string::cutField "${version1}" "${semVerIndex}" "."
+    semVerNumber1="${RETURNED_VALUE%%-*}"
+    semVerNumber1="${semVerNumber1%%+*}"
+    string::cutField "${version2}" "${semVerIndex}" "."
+    semVerNumber2="${RETURNED_VALUE%%-*}"
+    semVerNumber2="${semVerNumber2%%+*}"
+    if [[ ! ${semVerNumber1} =~ ^[0-9]+$ || ! ${semVerNumber2} =~ ^[0-9]+$ ]]; then
+      core::fail "Failed to compare versions ⌜${version1}⌝ and ⌜${version2}⌝ because they are not valid semantic versions."
+    elif (( semVerNumber1 > semVerNumber2 )); then
+      RETURNED_VALUE=1
+      return 0
+    elif (( semVerNumber1 < semVerNumber2 )); then
+      RETURNED_VALUE=-1
+      return 0
+    fi
+  done
+  RETURNED_VALUE=0
+}
+
 # ## string::bumpSemanticVersion
 #
 # This function allows to bump a semantic version formatted like:
@@ -92,7 +141,11 @@ function string::bumpSemanticVersion() {
   if [[ ${bumpLevel:-} == "minor" ]]; then level=1; fi
   local newVersion semVerString
   for semVerIndex in {0..2}; do
-    string::cutField "${version}" "${semVerIndex}" "." && semVerString="${RETURNED_VALUE%-*}"
+    string::cutField "${version}" "${semVerIndex}" "."
+    semVerString="${RETURNED_VALUE%-*}"
+    if [[ ! ${semVerString} =~ ^[0-9]+$ ]]; then
+      core::fail "Failed to bump the version ⌜${version}⌝ because it is not valid semantic version."
+    fi
     semVerNumber="${semVerString%+}"
     if [[ semVerIndex -eq level ]]; then semVerNumber=$((semVerNumber + 1)); fi
     if [[ semVerIndex -gt level ]]; then semVerNumber=0; fi
@@ -452,4 +505,4 @@ function string::regexGetFirst() {
   else
     RETURNED_VALUE=""
   fi
-}
\ No newline at end of file
+}
diff --git a/valet.d/version b/valet.d/version
index 66c0602..2408c26 100644
--- a/valet.d/version
+++ b/valet.d/version
@@ -1 +1 @@
-0.18.298
\ No newline at end of file
+0.18.301
\ No newline at end of file