Removes dupes from global history. Fixes column header.

Build.ps1

@@ -0,0 +1,2 @@
+rm ./Output -Recurse -Force
+Build-Module

Source/Public/f7_history.ps1

@@ -14,18 +14,44 @@ function f7_history {
 
   if ($global) {
     # Global history
-    $history = [Microsoft.PowerShell.PSConsoleReadLine]::GetHistoryItems().CommandLine
-    # reverse the items so most recent is on top
-    [array]::Reverse($history)
-    $selection = $history | Select-Object -Unique | Out-ConsoleGridView -OutputMode Single -Filter $line -Title "Command History for All Powershell Instances"
+    $historyItems = [Microsoft.PowerShell.PSConsoleReadLine]::GetHistoryItems()
+    [array]::Reverse($historyItems)
+
+    $seen = @{}
+    $history = $historyItems | Where-Object {
+      $key = $_.CommandLine
+      if (-not $seen.ContainsKey($key)) {
+        $seen[$key] = $true
+        return $true
+      }
+      return $false
+    } | ForEach-Object { 
+      $startTime = if ($_.StartTime -ne $null -and $_.StartTime -ne [datetime]::MinValue) { $_.StartTime.ToLocalTime() } else { $null }
+      [PSCustomObject]@{ 'CommandLine' = $_.CommandLine; 'When' = $startTime }
+    } 
+
+    if ($historyItems -eq $null -or $historyItems.Count -eq 0) {
+      Write-Host "The global (PSReadLine) history is empty."
+      return 
+    }
+
+    $selection = $history | Out-ConsoleGridView -OutputMode Single -Filter $line -Title "Command History for All Powershell Instances"
+
   }
   else {
     # Local history
-    $history = Get-History | Sort-Object -Descending -Property Id -Unique | Select-Object CommandLine -ExpandProperty CommandLine
+    $history = Get-History | Sort-Object -Descending -Property Id | Select-Object @{Name = 'CommandLine'; Expression = { $_.CommandLine } } -Unique
+
+    if ($history -eq $null -or $history.Count -eq 0) {
+      Write-Host "The PowerShell history is empty."
+      return 
+    }
+
     $selection = $history | Out-ConsoleGridView -OutputMode Single -Filter $line -Title "Command History"
   }
 
-  if ($selection) {
+  if ($selection.Count -gt 0) {
+    $selection = $selection.'CommandLine'
     [Microsoft.PowerShell.PSConsoleReadLine]::DeleteLine()
     [Microsoft.PowerShell.PSConsoleReadLine]::Insert($selection)
     if ($selection.StartsWith($line)) {
@@ -39,15 +65,16 @@ function f7_history {
 
 if ($args.Count -eq 0 -or $null -eq $args[0]["Key"]) {
   $key = "F7"
-} else {
+}
+else {
   $key = $args[0]["Key"]
 }
 
 # When F7 is pressed, show the local command line history in OCGV
 $parameters = @{
-  Key              = $key
+  Chord             = $key
   BriefDescription = 'Show Matching Command History'
-  LongDescription  = 'Show Matching Command History using Out-ConsoleGridView'
+  Description  = 'Show Matching Command History using Out-ConsoleGridView'
   ScriptBlock      = {
     f7_history -Global $false
   }
@@ -56,15 +83,16 @@ Set-PSReadLineKeyHandler @parameters
 
 if ($args.Count -eq 0 -or $null -eq $args[0]["AllKey"]) {
   $allkey = "Shift-F7"
-} else {
+}
+else {
   $allkey = $args[0]["AllKey"]
 }
 
 # When Shift-F7 is pressed, show the local command line history in OCGV
 $parameters = @{
-  Key              = $allkey
+  Chord              = $allkey
   BriefDescription = 'Show Matching Command History for All'
-  LongDescription  = 'Show Matching Command History for all PowerShell instances using Out-ConsoleGridView'
+  Description  = 'Show Matching Command History for all PowerShell instances using Out-ConsoleGridView'
   ScriptBlock      = {
     f7_history -Global $true
   }