Add UseCorrectParametersKind rule

Rules/Strings.resx

@@ -1236,4 +1236,19 @@
   <data name="AvoidReservedWordsAsFunctionNamesError" xml:space="preserve">
     <value>The reserved word '{0}' was used as a function name. This should be avoided.</value>
   </data>
+  <data name="UseCorrectParametersKindCommonName" xml:space="preserve">
+    <value>Use correct function parameters definition kind.</value>
+  </data>
+  <data name="UseCorrectParametersKindDescription" xml:space="preserve">
+    <value>Use consistent parameters definition kind to prevent potential unexpected behavior with inline functions parameters or param() block.</value>
+  </data>
+  <data name="UseCorrectParametersKindName" xml:space="preserve">
+    <value>UseCorrectParametersKind</value>
+  </data>
+  <data name="UseCorrectParametersKindInlineError" xml:space="preserve">
+    <value>Use param() block in function body instead of inline parameters.</value>
+  </data>
+  <data name="UseCorrectParametersKindParamBlockError" xml:space="preserve">
+    <value>Use inline parameters definition instead of param() block in function body.</value>
+  </data>
 </root>

Rules/UseCorrectParametersKind.cs

@@ -0,0 +1,171 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System;
+using System.Collections.Generic;
+#if !CORECLR
+using System.ComponentModel.Composition;
+#endif
+using System.Globalization;
+using System.Linq;
+using System.Management.Automation.Language;
+using Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic;
+
+namespace Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules
+{
+    /// <summary>
+    /// UseCorrectParametersKind: Checks if function parameters definition kind is same as preferred.
+    /// </summary>
+#if !CORECLR
+    [Export(typeof(IScriptRule))]
+#endif
+    public class UseCorrectParametersKind : ConfigurableRule
+    {
+        private enum ParametersDefinitionKind
+        {
+            Inline,
+            ParamBlock
+        }
+
+        private ParametersDefinitionKind parametersKind;
+
+        /// <summary>
+        /// Construct an object of UseCorrectParametersKind type.
+        /// </summary>
+        public UseCorrectParametersKind() : base()
+        {
+            Enable = false;  // Disable rule by default
+        }
+
+        /// <summary>
+        /// The type of preferred parameters definition for functions.
+        ///
+        /// Default value is "ParamBlock".
+        /// </summary>
+        [ConfigurableRuleProperty(defaultValue: "ParamBlock")]
+        public string ParametersKind
+        {
+            get
+            {
+                return parametersKind.ToString();
+            }
+            set
+            {
+                if (String.IsNullOrWhiteSpace(value) ||
+                    !Enum.TryParse<ParametersDefinitionKind>(value, true, out parametersKind))
+                {
+                    parametersKind = ParametersDefinitionKind.ParamBlock;
+                }
+            }
+        }
+
+        /// <summary>
+        /// AnalyzeScript: Analyze the script to check if any function is using not preferred parameters kind.
+        /// </summary>
+        public override IEnumerable<DiagnosticRecord> AnalyzeScript(Ast ast, string fileName)
+        {
+            if (ast == null) { throw new ArgumentNullException(Strings.NullAstErrorMessage); }
+
+            IEnumerable<Ast> functionAsts = ast.FindAll(testAst => testAst is FunctionDefinitionAst, true);
+            if (parametersKind == ParametersDefinitionKind.ParamBlock)
+            {
+                return checkInlineParameters(functionAsts, fileName);
+            }
+            else
+            {
+                return checkParamBlockParameters(functionAsts, fileName);
+            }
+        }
+
+        private IEnumerable<DiagnosticRecord> checkInlineParameters(IEnumerable<Ast> functionAsts, string fileName)
+        {
+            foreach (FunctionDefinitionAst functionAst in functionAsts)
+            {
+                if (functionAst.Parameters != null)
+                {
+                    yield return new DiagnosticRecord(
+                        string.Format(CultureInfo.CurrentCulture, Strings.UseCorrectParametersKindInlineError, functionAst.Name),
+                        functionAst.Extent,
+                        GetName(),
+                        GetDiagnosticSeverity(),
+                        fileName
+                    );
+                }
+            }
+        }
+
+        private IEnumerable<DiagnosticRecord> checkParamBlockParameters(IEnumerable<Ast> functionAsts, string fileName)
+        {
+            foreach (FunctionDefinitionAst functionAst in functionAsts)
+            {
+                if (functionAst.Body.ParamBlock != null)
+                {
+                    yield return new DiagnosticRecord(
+                        string.Format(CultureInfo.CurrentCulture, Strings.UseCorrectParametersKindParamBlockError, functionAst.Name),
+                        functionAst.Extent,
+                        GetName(),
+                        GetDiagnosticSeverity(),
+                        fileName
+                    );
+                }
+            }
+        }
+
+        /// <summary>
+        /// Retrieves the common name of this rule.
+        /// </summary>
+        public override string GetCommonName()
+        {
+            return string.Format(CultureInfo.CurrentCulture, Strings.UseCorrectParametersKindCommonName);
+        }
+
+        /// <summary>
+        /// Retrieves the description of this rule.
+        /// </summary>
+        public override string GetDescription()
+        {
+            return string.Format(CultureInfo.CurrentCulture, Strings.UseCorrectParametersKindDescription);
+        }
+
+        /// <summary>
+        /// Retrieves the name of this rule.
+        /// </summary>
+        public override string GetName()
+        {
+            return string.Format(CultureInfo.CurrentCulture, Strings.NameSpaceFormat, GetSourceName(), Strings.UseCorrectParametersKindName);
+        }
+
+        /// <summary>
+        /// Retrieves the severity of the rule: error, warning or information.
+        /// </summary>
+        public override RuleSeverity GetSeverity()
+        {
+            return RuleSeverity.Warning;
+        }
+
+        /// <summary>
+        /// Gets the severity of the returned diagnostic record: error, warning, or information.
+        /// </summary>
+        /// <returns></returns>
+        public DiagnosticSeverity GetDiagnosticSeverity()
+        {
+            return DiagnosticSeverity.Warning;
+        }
+
+        /// <summary>
+        /// Retrieves the name of the module/assembly the rule is from.
+        /// </summary>
+        public override string GetSourceName()
+        {
+            return string.Format(CultureInfo.CurrentCulture, Strings.SourceName);
+        }
+
+        /// <summary>
+        /// Retrieves the type of the rule, Builtin, Managed or Module.
+        /// </summary>
+        public override SourceType GetSourceType()
+        {
+            return SourceType.Builtin;
+        }
+    }
+}

Tests/Engine/GetScriptAnalyzerRule.tests.ps1

@@ -63,7 +63,7 @@ Describe "Test Name parameters" {
 
         It "get Rules with no parameters supplied" {
             $defaultRules = Get-ScriptAnalyzerRule
-            $expectedNumRules = 71
+            $expectedNumRules = 72
             if ($PSVersionTable.PSVersion.Major -le 4)
             {
                 # for PSv3 PSAvoidGlobalAliases is not shipped because