Fix for /define acting like a switch instead of a parameter due to quoting

Issue #16
All 54 tests pass

Author: darianmiller

CHANGELOG.md

@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 
 ---
 
+## [0.5.0] - Unreleased
+
+- Define parameter broken - MSBuild thinks it's a switch
+  [#16](https://github.com/continuous-delphi/delphi-msbuild/issues/16)
+  
 ## [0.4.0] - 2026-03-17
 
 - Ensure `PowerShell 5.1` compatibility for the delphi-msbuild.ps1 script

source/delphi-msbuild.ps1

@@ -213,9 +213,14 @@ function Invoke-MsbuildProject {
     $msbuildArgs += "/p:DCC_UnitSearchPath=$unitSearchValue"
   }
 
+  if ($UnitSearchPath.Count -gt 0) {
+    $unitSearchValue = '$(DCC_UnitSearchPath);' + ($UnitSearchPath -join ';')
+    $msbuildArgs += "/p:DCC_UnitSearchPath=`"$unitSearchValue`""
+  }
+
   if ($Define.Count -gt 0) {
     $defineValue = '$(DCC_Define);' + ($Define -join ';')
-    $msbuildArgs += "/p:DCC_Define=$defineValue"
+    $msbuildArgs += "/p:DCC_Define=`"$defineValue`""
   }
 
   return Invoke-MsbuildExe -Arguments $msbuildArgs -ShowOutput:$ShowOutput

tests/pwsh/delphi-msbuild.Tests.ps1

@@ -508,8 +508,8 @@ Describe 'Invoke-MsbuildProject' {
         -Define      @('MYFLAG')
     }
 
-    It 'includes /p:DCC_Define=$(DCC_Define);MYFLAG' {
-      $script:capturedArgs | Should -Contain '/p:DCC_Define=$(DCC_Define);MYFLAG'
+    It 'includes /p:DCC_Define="$(DCC_Define);MYFLAG"' {
+      $script:capturedArgs | Should -Contain '/p:DCC_Define="$(DCC_Define);MYFLAG"'
     }
 
   }
@@ -532,8 +532,8 @@ Describe 'Invoke-MsbuildProject' {
         -Define      @('MYFLAG', 'USE_JEDI_JCL')
     }
 
-    It 'includes /p:DCC_Define=$(DCC_Define);MYFLAG;USE_JEDI_JCL' {
-      $script:capturedArgs | Should -Contain '/p:DCC_Define=$(DCC_Define);MYFLAG;USE_JEDI_JCL'
+    It 'includes /p:DCC_Define="$(DCC_Define);MYFLAG;USE_JEDI_JCL"' {
+      $script:capturedArgs | Should -Contain '/p:DCC_Define="$(DCC_Define);MYFLAG;USE_JEDI_JCL"'
     }
 
   }