Add -FuzzyMinimumDistance parameter to Get-Command (PowerShell#18261)

Author: SteveL-MSFT

src/System.Management.Automation/engine/GetCommandCommand.cs

@@ -339,7 +339,13 @@ public PSTypeName[] ParameterType
         [Parameter(ParameterSetName = "AllCommandSet")]
         public SwitchParameter UseFuzzyMatching { get; set; }
 
-        private readonly List<CommandScore> _commandScores = new List<CommandScore>();
+        /// <summary>
+        /// Gets or sets the minimum fuzzy matching distance.
+        /// </summary>
+        [Parameter(ParameterSetName = "AllCommandSet")]
+        public uint FuzzyMinimumDistance { get; set; } = 5;
+
+        private List<CommandScore> _commandScores = new List<CommandScore>();
 
         /// <summary>
         /// Gets or sets the parameter that determines if return cmdlets based on abbreviation expansion.
@@ -501,13 +507,16 @@ private void OutputResultsHelper(IEnumerable<CommandInfo> results)
 
             if (UseFuzzyMatching)
             {
-                results = _commandScores.OrderBy(static x => x.Score).Select(static x => x.Command).ToList();
+                _commandScores = _commandScores
+                    .Where(x => x.Score <= FuzzyMinimumDistance)
+                    .OrderBy(static x => x.Score)
+                    .ToList();
+                results = _commandScores.Select(static x => x.Command);
             }
 
             int count = 0;
             foreach (CommandInfo result in results)
             {
-                count += 1;
                 // Only write the command if it is visible to the requestor
                 if (SessionState.IsVisible(origin, result))
                 {
@@ -532,11 +541,21 @@ private void OutputResultsHelper(IEnumerable<CommandInfo> results)
                         }
                         else
                         {
-                            // Write output as normal command info object.
-                            WriteObject(result);
+                            if (UseFuzzyMatching)
+                            {
+                                PSObject obj = new PSObject(result);
+                                obj.Properties.Add(new PSNoteProperty("Score", _commandScores[count].Score));
+                                WriteObject(obj);
+                            }
+                            else
+                            {
+                                WriteObject(result);
+                            }
                         }
                     }
                 }
+
+                count += 1;
             }
 
 #if LEGACYTELEMETRY

test/powershell/Modules/Microsoft.PowerShell.Utility/Get-Command.Tests.ps1

@@ -7,6 +7,7 @@ Describe "Get-Command Feature tests" -Tag Feature {
             $cmds = Get-Command get-hlp -UseFuzzyMatch
             $cmds.Count | Should -BeGreaterThan 0
             $cmds[0].Name | Should -BeExactly 'Get-Help' -Because "This should be closest match so shows up first"
+            $cmds[0].Score | Should -Be 1
         }
 
         It "Should match native commands" {
@@ -20,6 +21,14 @@ Describe "Get-Command Feature tests" -Tag Feature {
             $cmds.Count | Should -BeGreaterThan 0
             $cmds.Name | Should -Contain $expectedcmd
         }
+
+        It "Should use minimum distance" {
+            $cmds = Get-Command get-hlp -UseFuzzyMatch -FuzzyMinimumDistance 3
+            $cmds.Count | Should -BeGreaterThan 0
+            foreach ($cmd in $cmds) {
+                $cmd.Score | Should -BeLessOrEqual 3
+            }
+        }
     }
 
     Context "-UseAbbreviationExpansion tests" {