fix(scoop-alias): Prevent overwrite existing file when adding alias

CHANGELOG.md

@@ -46,6 +46,7 @@
 - **update/uninstall:** Remove items from PATH correctly ([#5833](https://github.com/ScoopInstaller/Scoop/issues/5833))
 - **shim:** Allow GUI applications to attach to the shell's console when launched using the GUI shim ([#5721](https://github.com/ScoopInstaller/Scoop/issues/5721))
 - **core:** Fix arguments parsing method of `Invoke-ExternalCommand()` ([#5839](https://github.com/ScoopInstaller/Scoop/issues/5839))
+- **scoop-alias:** Prevent overwrite existing file when adding alias ([#5577](https://github.com/ScoopInstaller/Scoop/issues/5577))
 
 ### Performance Improvements
 

libexec/scoop-alias.ps1

@@ -44,13 +44,16 @@ function add_alias($name, $command) {
     # get current aliases from config
     $aliases = init_alias_config
     if ($aliases.$name) {
-        abort "Alias $name already exists."
+        abort "Alias '$name' already exists."
     }
 
     $alias_file = "scoop-$name"
 
     # generate script
     $shimdir = shimdir $false
+    if (Test-Path "$shimdir\$alias_file.ps1") {
+        abort "File '$alias_file.ps1' already exists in shims directory."
+    }
     $script =
     @(
         "# Summary: $description",
@@ -67,18 +70,18 @@ function add_alias($name, $command) {
 function rm_alias($name) {
     $aliases = init_alias_config
     if (!$name) {
-        abort 'Which alias should be removed?'
+        abort 'Alias to be removed has not been specified!'
     }
 
     if ($aliases.$name) {
-        "Removing alias $name..."
+        info "Removing alias '$name'..."
 
         rm_shim $aliases.$name (shimdir $false)
 
         $aliases.PSObject.Properties.Remove($name)
         set_config $script:config_alias $aliases | Out-Null
     } else {
-        abort "Alias $name doesn't exist."
+        abort "Alias '$name' doesn't exist."
     }
 }
 

test/Scoop-Alias.Tests.ps1

@@ -8,7 +8,7 @@ BeforeAll {
 Describe 'Manipulate Alias' -Tag 'Scoop' {
     BeforeAll {
         Mock shimdir { "$TestDrive\shims" }
-        Mock set_config { }
+        Mock set_config {}
         Mock get_config { @{} }
 
         $shimdir = shimdir
@@ -23,23 +23,24 @@ Describe 'Manipulate Alias' -Tag 'Scoop' {
         & $alias_file | Should -Be 'hello, world!'
     }
 
-    It 'Does not change existing alias if alias exists' {
+    It 'Does not change existing file if its filename same as alias name' {
         $alias_file = "$shimdir\scoop-rm.ps1"
+        Mock abort {}
         New-Item $alias_file -Type File -Force
         $alias_file | Should -Exist
 
-        add_alias 'rm' 'test'
-        & $alias_file | Should -Not -Be 'test'
+        add_alias 'rm' '"test"'
+        Should -Invoke -CommandName abort -Times 1 -ParameterFilter { $msg -eq "File 'scoop-rm.ps1' already exists in shims directory." }
     }
 
     It 'Removes an existing alias' {
         $alias_file = "$shimdir\scoop-rm.ps1"
-        add_alias 'rm' '"hello, world!"'
-
         $alias_file | Should -Exist
         Mock get_config { @(@{'rm' = 'scoop-rm' }) }
+        Mock info {}
 
         rm_alias 'rm'
         $alias_file | Should -Not -Exist
+        Should -Invoke -CommandName info -Times 1 -ParameterFilter { $msg -eq "Removing alias 'rm'..." }
     }
 }

test/Scoop-Versions.Tests.ps1

@@ -99,7 +99,7 @@ Describe 'versions comparison' -Tag 'Scoop' {
             Compare-Version 'nightly-20190801' 'nightly-20200801' | Should -Be 0
         }
 
-        It 'handles nightly versions with `update_nightly`' {
+        It "handles nightly versions with 'update_nightly'" {
             function get_config { $true }
             Mock Get-Date { '20200801' }
             Compare-Version 'nightly-20200801' 'nightly' | Should -Be 0