Added support for split and concat functions during policy export A…

…zure#2851 (Azure#2908)
BenjaminEngeset · Jun 4, 2024 · 5e5a82e · 5e5a82e
1 parent 8bd4055
commit 5e5a82e
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Showing 11 changed files with 448 additions and 218 deletions.
diff --git a/docs/CHANGELOG-v1.md b/docs/CHANGELOG-v1.md
@@ -46,6 +46,9 @@ See [upgrade notes][1] for helpful information when upgrading from previous vers
       - Removed the `If` Premium SKU.
       - Added check for Premium SKU.
       - Bumped rule set to `2024_06`
+- General improvements:
+  - Added support for `split` and `concat` functions during policy export by @BernieWhite.
+    [#2851](https://github.com/Azure/PSRule.Rules.Azure/issues/2851)
 - Engineering:
   - Bump xunit to v2.8.1.
     [#2892](https://github.com/Azure/PSRule.Rules.Azure/pull/2892)

diff --git a/src/PSRule.Rules.Azure/Data/Policy/PolicyAssignmentVisitor.cs b/src/PSRule.Rules.Azure/Data/Policy/PolicyAssignmentVisitor.cs
@@ -76,6 +76,11 @@ internal abstract class PolicyAssignmentVisitor : ResourceManagerVisitor
         private const string PROPERTY_HASVALUE = "hasValue";
         private const string PROPERTY_EMPTY = "empty";
         private const string PROPERTY_LENGTH = "length";
+        private const string PROPERTY_CONCAT = "concat";
+        private const string PROPERTY_SPLIT = "split";
+        private const string PROPERTY_STRING = "string";
+        private const string PROPERTY_INTEGER = "integer";
+        private const string PROPERTY_DELIMITER = "delimiter";
 
         private const string EFFECT_DISABLED = "Disabled";
         private const string EFFECT_AUDITIFNOTEXISTS = "AuditIfNotExists";
@@ -1291,7 +1296,7 @@ private static JObject VisitValueExpression(PolicyAssignmentContext context, JOb
             }
 
             // Handle [field('string')]
-            else if (tokens.HasFieldTokens())
+            else if (tokens.HasFieldTokens() && !tokens.HasPolicyRuntimeTokens())
             {
                 condition = VisitFieldTokens(context, condition, tokens);
             }
@@ -1331,14 +1336,14 @@ private static JObject VisitFieldTokens(PolicyAssignmentContext context, JObject
             else if (tokens.ConsumeFunction(PROPERTY_IF) &&
                 tokens.TryTokenType(ExpressionTokenType.GroupStart, out _))
             {
-                var orginal = condition;
+                var original = condition;
 
                 // Condition
                 var leftCondition = VisitFieldTokens(context, new JObject(), tokens);
                 var rightCondition = ReverseCondition(Clone(leftCondition));
 
-                var leftEvaluation = VisitFieldTokens(context, Clone(orginal), tokens);
-                var rightEvaluation = VisitFieldTokens(context, Clone(orginal), tokens);
+                var leftEvaluation = VisitFieldTokens(context, Clone(original), tokens);
+                var rightEvaluation = VisitFieldTokens(context, Clone(original), tokens);
 
                 var left = new JObject
                 {
@@ -1498,6 +1503,8 @@ private static JObject VisitFieldTokens(PolicyAssignmentContext context, JObject
         private static JObject VisitRuntimeTokens(PolicyAssignmentContext context, TokenStream tokens)
         {
             var o = VisitRuntimeToken(context, tokens);
+            if (tokens.Count > 0) throw new NotImplementedException(string.Format(Thread.CurrentThread.CurrentCulture, PSRuleResources.PolicyRuntimeTokenNotProcessed, tokens.AsString()));
+
             return o == null ? null : new JObject
             {
                 { DOLLAR, o }
@@ -1524,7 +1531,7 @@ private static JObject VisitRuntimeToken(PolicyAssignmentContext context, TokenS
             }
             else if (tokens.ConsumeFunction(FUNCTION_CURRENT) && tokens.Skip(ExpressionTokenType.GroupStart))
             {
-                var fieldTarget = "";
+                var fieldTarget = string.Empty;
                 if (tokens.TryTokenType(ExpressionTokenType.String, out var current))
                 {
                     fieldTarget = current.Content;
@@ -1538,6 +1545,72 @@ private static JObject VisitRuntimeToken(PolicyAssignmentContext context, TokenS
                 tokens.Skip(ExpressionTokenType.GroupEnd);
                 return o;
             }
+            else if (tokens.ConsumeFunction(PROPERTY_CONCAT) &&
+                tokens.TryTokenType(ExpressionTokenType.GroupStart, out _))
+            {
+                var items = new JArray();
+
+                while (tokens.Current.Type == ExpressionTokenType.Element ||
+                    tokens.Current.Type == ExpressionTokenType.String)
+                {
+                    var child = VisitRuntimeToken(context, tokens);
+                    items.Add(child);
+                }
+                var o = new JObject
+                {
+                    [PROPERTY_CONCAT] = items
+                };
+                tokens.TryTokenType(ExpressionTokenType.GroupEnd, out _);
+                return o;
+            }
+            else if (tokens.ConsumeFunction(PROPERTY_SPLIT) &&
+                tokens.TryTokenType(ExpressionTokenType.GroupStart, out _))
+            {
+                var child = VisitRuntimeToken(context, tokens);
+
+                var delimiter = new JArray();
+                if (tokens.ConsumeString(out var d))
+                {
+                    delimiter.Add(d);
+                }
+
+                var o = new JObject
+                {
+                    { PROPERTY_SPLIT, child },
+                    { PROPERTY_DELIMITER, delimiter }
+                };
+                tokens.TryTokenType(ExpressionTokenType.GroupEnd, out _);
+                return o;
+            }
+            else if (tokens.ConsumeFunction(PROPERTY_FIELD) &&
+                tokens.TryTokenType(ExpressionTokenType.GroupStart, out _) &&
+                tokens.ConsumeString(out var field))
+            {
+                field = context.TryPolicyAliasPath(field, out var aliasPath) ? TrimFieldName(context, aliasPath) : field;
+
+                var o = new JObject
+                {
+                    { PROPERTY_PATH, field }
+                };
+                tokens.TryTokenType(ExpressionTokenType.GroupEnd, out _);
+                return o;
+            }
+            else if (tokens.ConsumeString(out var s))
+            {
+                var o = new JObject
+                {
+                    { PROPERTY_STRING, s }
+                };
+                return o;
+            }
+            else if (tokens.ConsumeInteger(out var i))
+            {
+                var o = new JObject
+                {
+                    { PROPERTY_INTEGER, i }
+                };
+                return o;
+            }
             return null;
         }
 

diff --git a/src/PSRule.Rules.Azure/Data/Template/ExpressionToken.cs b/src/PSRule.Rules.Azure/Data/Template/ExpressionToken.cs
@@ -0,0 +1,30 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System.Diagnostics;
+
+namespace PSRule.Rules.Azure.Data.Template
+{
+    /// <summary>
+    /// An individual expression token.
+    /// </summary>
+    [DebuggerDisplay("Type = {Type}, Content = {Content}")]
+    internal sealed class ExpressionToken
+    {
+        internal readonly ExpressionTokenType Type;
+        internal readonly long Value;
+        internal readonly string Content;
+
+        internal ExpressionToken(ExpressionTokenType type, string content)
+        {
+            Type = type;
+            Content = content;
+        }
+
+        internal ExpressionToken(long value)
+        {
+            Type = ExpressionTokenType.Numeric;
+            Value = value;
+        }
+    }
+}
diff --git a/src/PSRule.Rules.Azure/Data/Template/ExpressionTokenType.cs b/src/PSRule.Rules.Azure/Data/Template/ExpressionTokenType.cs
@@ -0,0 +1,57 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+namespace PSRule.Rules.Azure.Data.Template
+{
+    /// <summary>
+    /// The available token types used for Azure Resource Manager expressions.
+    /// </summary>
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("Naming", "CA1720:Identifier contains type name", Justification = "Represents standard type.")]
+    public enum ExpressionTokenType : byte
+    {
+        /// <summary>
+        /// Null token.
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// A function name.
+        /// </summary>
+        Element,
+
+        /// <summary>
+        /// A property <c>.property_name</c>.
+        /// </summary>
+        Property,
+
+        /// <summary>
+        /// A string literal.
+        /// </summary>
+        String,
+
+        /// <summary>
+        /// A numeric literal.
+        /// </summary>
+        Numeric,
+
+        /// <summary>
+        /// Start a grouping <c>'('</c>.
+        /// </summary>
+        GroupStart,
+
+        /// <summary>
+        /// End a grouping <c>')'</c>.
+        /// </summary>
+        GroupEnd,
+
+        /// <summary>
+        /// Start an index <c>'['</c>.
+        /// </summary>
+        IndexStart,
+
+        /// <summary>
+        /// End an index <c>']'</c>.
+        /// </summary>
+        IndexEnd
+    }
+}