Allow ability to change powershell version

autoload/coc/powershell.vim

@@ -1,8 +1,8 @@
 let s:root           = expand('<sfile>:h:h:h')
 let s:is_win         = has('win32') || has('win64')
 let s:is_mac         = !s:is_win && !has('win32unix')
-      \ && (has('mac') || has('macunix') || has('gui_macvim') ||
-      \   (!isdirectory('/proc') && executable('sw_vers')))
+    \ && (has('mac') || has('macunix') || has('gui_macvim') ||
+    \   (!isdirectory('/proc') && executable('sw_vers')))
 let s:is_vim         = !has('nvim')
 let s:install_script = s:root.'/install.ps1'
 

autoload/coc/powershell/utils.vim

@@ -0,0 +1,80 @@
+let s:is_win         = has('win32') || has('win64')
+let s:is_mac = !s:is_win && !has('win32unix')
+    \ && (has('mac') || has('macunix') || has('gui_macvim') ||
+    \   (!isdirectory('/proc') && executable('sw_vers')))
+
+let s:linuxExe        = { "versionName": "PowerShell Core", "executablePath": "/usr/bin/pwsh" }
+let s:linuxPreviewExe = { "versionName": "PowerShell Core Preview", "executablePath": "/usr/bin/pwsh-preview" }
+let s:snapExe         = { "versionName": "PowerShell Core Snap", "executablePath": "/snap/bin/pwsh" }
+let s:snapPreviewExe  = { "versionName": "PowerShell Core Preview Snap", "executablePath": "/snap/bin/pwsh-preview" }
+let s:macOSExe        = { "versionName": "PowerShell Core", "executablePath": "/usr/local/bin/pwsh" }
+let s:macOSPreviewExe = { "versionName": "PowerShell Core Preview", "executablePath": "/usr/local/bin/pwsh-preview" }
+
+function! s:getAvailablePowerShellExecutables ()
+    let paths = []
+    if(s:is_win)
+        call add(paths, {
+            \ versionName: "Windows PowerShell",
+            \ executablePath: "C:\\System32\\WindowsPowerShell\\v1.0\\powershell.exe"
+            \ })
+
+        let psCoreInstallPath = "C:\\System32\\PowerShell\\"
+        if(isdirectory(psCoreInstallPath))
+            let psCoreExePaths = split(glob(psCoreInstallPath . "**\\pwsh.exe"), "\n")
+            if(!empty(psCoreExePaths))
+                call add(paths, {
+                    \ versionName: "PowerShell Core",
+                    \ executablePath: psCoreExePaths[0]
+                    \ })
+            endif
+        endif
+
+        return paths
+    endif
+
+    " macOS and Linux
+    let powershellExecutables = [ s:linuxExe, s:linuxPreviewExe, s:snapExe, s:snapPreviewExe ]
+    if(s:is_mac)
+        let powershellExecutables = [ s:macOSExe, s:macOSPreviewExe ]
+    endif
+
+    for powershellExecutable in powershellExecutables
+        if(filereadable(powershellExecutable.executablePath))
+            call add(paths, powershellExecutable)
+        endif
+    endfor
+
+    return paths
+endfunction
+
+function! coc#powershell#utils#switch_powershell_executable (...)
+    let s:choice = ""
+    if(!exists("a:1"))
+        let powershellExecutables = s:getAvailablePowerShellExecutables()
+        let index = 1
+        let choiceStr = ""
+        while(index <= len(powershellExecutables))
+            let choiceStr = choiceStr . index . " " . powershellExecutables[index - 1].versionName
+            if(index != len(powershellExecutables))
+                let choiceStr = choiceStr . "\n"
+            endif
+            let index = index + 1
+        endwhile
+        let s:choice = powershellExecutables[confirm("Which PowerShell executable would you like to use?", choiceStr) - 1].executablePath
+    else
+        let s:choice = a:1
+    endif
+
+    if(!executable(s:choice))
+        throw "Executable not found: " . s:choice
+    endif
+
+    if(g:pses_powershell_executable == s:choice)
+        echo "PowerShell executable already set to: " . s:choice
+    else
+        let g:pses_powershell_executable = s:choice
+
+        echo "Restarting coc client to apply change..."
+        call coc#client#restart_all()
+    endif
+endfunction