From a26a560d9306468a66af406a62836e8a83304eca Mon Sep 17 00:00:00 2001
From: Chawye Hsu <su+git@chawyehsu.com>
Date: Thu, 27 Aug 2026 12:19:07 +0800
Subject: [PATCH 1/3] refactor!: guard install flow against dot-sourcing

Signed-off-by: Chawye Hsu <su+git@chawyehsu.com>
---
 install.ps1            | 30 ++++++++++++++----------------
 test/install.Tests.ps1 |  6 ++++++
 2 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/install.ps1 b/install.ps1
index fa78c2a..ad17208 100644
--- a/install.ps1
+++ b/install.ps1
@@ -575,10 +575,10 @@ function Test-CommandAvailable {
 
 function Install-Scoop {
     Write-InstallInfo 'Initializing...'
-    # Validate install parameters
-    Test-ValidateParameter
     # Check prerequisites
     Test-Prerequisite
+    # Validate install parameters
+    Test-ValidateParameter
     # Enable TLS 1.2
     Optimize-SecurityProtocol
 
@@ -680,12 +680,12 @@ function Write-DebugInfo {
     Write-Verbose "SCOOP_CONFIG_HOME: $SCOOP_CONFIG_HOME"
 }
 
+# Quit if anything goes wrong
+$ErrorActionPreference = 'Stop'
+
 # Prepare variables
 $IS_EXECUTED_FROM_IEX = ($null -eq $MyInvocation.MyCommand.Path)
 
-# Abort when the language mode is restricted
-Test-LanguageMode
-
 # Scoop root directory
 $SCOOP_DIR = $ScoopDir, $env:SCOOP, "$env:USERPROFILE\scoop" | Where-Object { -not [String]::IsNullOrEmpty($_) } | Select-Object -First 1
 # Scoop global apps directory
@@ -709,14 +709,12 @@ $SCOOP_MAIN_BUCKET_REPO = 'https://github.com/ScoopInstaller/Main/archive/master
 $SCOOP_PACKAGE_GIT_REPO = 'https://github.com/ScoopInstaller/Scoop.git'
 $SCOOP_MAIN_BUCKET_GIT_REPO = 'https://github.com/ScoopInstaller/Main.git'
 
-# Quit if anything goes wrong
-$oldErrorActionPreference = $ErrorActionPreference
-$ErrorActionPreference = 'Stop'
-
-# Logging debug info
-Write-DebugInfo $PSBoundParameters
-# Bootstrap function
-Install-Scoop
-
-# Reset $ErrorActionPreference to original value
-$ErrorActionPreference = $oldErrorActionPreference
+# The install flow triggers only when the script is executed directly, but
+# not when dot-sourced. Dot-sourcing the installer will not trigger the
+# installation, and only the functions will be loaded, e.g., for testing.
+# Downstreams can call `Install-Scoop` explicitly to start the installation.
+if ($MyInvocation.InvocationName -ne '.') {
+    Test-LanguageMode
+    Write-DebugInfo $PSBoundParameters
+    Install-Scoop
+}
diff --git a/test/install.Tests.ps1 b/test/install.Tests.ps1
index 806aa0d..e77a567 100644
--- a/test/install.Tests.ps1
+++ b/test/install.Tests.ps1
@@ -1,4 +1,10 @@
 BeforeAll {
+    $script:TestScoopDir = Join-Path $TestDrive 'scoop'
+    $script:TestGlobalDir = Join-Path $TestDrive 'scoop-global'
+
+    $env:SCOOP = $script:TestScoopDir
+    $env:SCOOP_GLOBAL = $script:TestGlobalDir
+
     # Load SUT
     $sut = (Split-Path -Leaf $PSCommandPath).Replace('.Tests.ps1', '.ps1')
     . ".\$sut"

From 53829d1d2cb00721baf21e50fbb213c1bf7619d8 Mon Sep 17 00:00:00 2001
From: Chawye Hsu <su+git@chawyehsu.com>
Date: Thu, 27 Aug 2026 12:40:19 +0800
Subject: [PATCH 2/3] test: remove intermediate variables

Signed-off-by: Chawye Hsu <su+git@chawyehsu.com>
---
 test/install.Tests.ps1 | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/test/install.Tests.ps1 b/test/install.Tests.ps1
index e77a567..1c93d39 100644
--- a/test/install.Tests.ps1
+++ b/test/install.Tests.ps1
@@ -1,9 +1,6 @@
 BeforeAll {
-    $script:TestScoopDir = Join-Path $TestDrive 'scoop'
-    $script:TestGlobalDir = Join-Path $TestDrive 'scoop-global'
-
-    $env:SCOOP = $script:TestScoopDir
-    $env:SCOOP_GLOBAL = $script:TestGlobalDir
+    $env:SCOOP = Join-Path $TestDrive 'scoop'
+    $env:SCOOP_GLOBAL = Join-Path $TestDrive 'scoop-global'
 
     # Load SUT
     $sut = (Split-Path -Leaf $PSCommandPath).Replace('.Tests.ps1', '.ps1')

From a36b3c4694cb28d80ade9eca08cc02307d23aefa Mon Sep 17 00:00:00 2001
From: Chawye Hsu <su+git@chawyehsu.com>
Date: Thu, 27 Aug 2026 12:46:29 +0800
Subject: [PATCH 3/3] fix: restore caller error preference

Signed-off-by: Chawye Hsu <su+git@chawyehsu.com>
---
 install.ps1 | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/install.ps1 b/install.ps1
index ad17208..82d311d 100644
--- a/install.ps1
+++ b/install.ps1
@@ -680,9 +680,6 @@ function Write-DebugInfo {
     Write-Verbose "SCOOP_CONFIG_HOME: $SCOOP_CONFIG_HOME"
 }
 
-# Quit if anything goes wrong
-$ErrorActionPreference = 'Stop'
-
 # Prepare variables
 $IS_EXECUTED_FROM_IEX = ($null -eq $MyInvocation.MyCommand.Path)
 
@@ -714,7 +711,13 @@ $SCOOP_MAIN_BUCKET_GIT_REPO = 'https://github.com/ScoopInstaller/Main.git'
 # installation, and only the functions will be loaded, e.g., for testing.
 # Downstreams can call `Install-Scoop` explicitly to start the installation.
 if ($MyInvocation.InvocationName -ne '.') {
-    Test-LanguageMode
-    Write-DebugInfo $PSBoundParameters
-    Install-Scoop
+    $oldErrorActionPreference = $ErrorActionPreference
+    try {
+        $ErrorActionPreference = 'Stop'
+        Test-LanguageMode
+        Write-DebugInfo $PSBoundParameters
+        Install-Scoop
+    } finally {
+        $ErrorActionPreference = $oldErrorActionPreference
+    }
 }