Implement decompilation for the 'scope' property (#1190)

Author: anthony-c-martin

src/Bicep.Decompiler.IntegrationTests/Working/extensionresource/main.bicep

@@ -0,0 +1,40 @@
+param hostingPlanName string
+param location string = resourceGroup().location
+
+var siteName_var = 'ExampleSite${uniqueString(resourceGroup().id)}'
+
+resource hostingPlanName_resource 'Microsoft.Web/serverfarms@2020-06-01' = {
+  name: hostingPlanName
+  location: location
+  sku: {
+    tier: 'Free'
+    name: 'f1'
+    capacity: 0
+  }
+  properties: {
+    targetWorkerCount: 1
+  }
+}
+
+resource siteName 'Microsoft.Web/sites@2020-06-01' = {
+  name: siteName_var
+  location: location
+  properties: {
+    serverFarmId: hostingPlanName
+  }
+  dependsOn: [
+    hostingPlanName_resource
+  ]
+}
+
+resource siteLock 'Microsoft.Authorization/locks@2016-09-01' = {
+  name: 'siteLock'
+  properties: {
+    level: 'CanNotDelete'
+    notes: 'Site should not be deleted.'
+  }
+  scope: siteName
+  dependsOn: [
+    siteName
+  ]
+}

src/Bicep.Decompiler.IntegrationTests/Working/extensionresource/main.json

@@ -0,0 +1,57 @@
+{
+  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
+  "contentVersion": "1.0.0.0",
+  "parameters": {
+    "hostingPlanName": {
+      "type": "string"
+    },
+    "location": {
+        "type": "string",
+        "defaultValue": "[resourceGroup().location]"
+    }
+  },
+  "variables": {
+    "siteName": "[concat('ExampleSite', uniqueString(resourceGroup().id))]"
+  },
+  "resources": [
+    {
+      "type": "Microsoft.Web/serverfarms",
+      "apiVersion": "2020-06-01",
+      "name": "[parameters('hostingPlanName')]",
+      "location": "[parameters('location')]",
+      "sku": {
+        "tier": "Free",
+        "name": "f1",
+        "capacity": 0
+      },
+      "properties": {
+        "targetWorkerCount": 1
+      }
+    },
+    {
+      "type": "Microsoft.Web/sites",
+      "apiVersion": "2020-06-01",
+      "name": "[variables('siteName')]",
+      "location": "[parameters('location')]",
+      "dependsOn": [
+        "[resourceId('Microsoft.Web/serverfarms', parameters('hostingPlanName'))]"
+      ],
+      "properties": {
+        "serverFarmId": "[parameters('hostingPlanName')]"
+      }
+    },
+    {
+      "type": "Microsoft.Authorization/locks",
+      "apiVersion": "2016-09-01",
+      "name": "siteLock",
+      "scope": "[concat('Microsoft.Web/sites/', variables('siteName'))]",
+      "dependsOn": [
+        "[resourceId('Microsoft.Web/sites', variables('siteName'))]"
+      ],
+      "properties": {
+        "level": "CanNotDelete",
+        "notes": "Site should not be deleted."
+      }
+    }
+  ]
+}

src/Bicep.Decompiler/TemplateConverter.cs

@@ -639,28 +639,28 @@ StringSyntax createFakeModulePath(string templateLinkExpression)
             return SyntaxHelpers.CreateStringLiteral(filePath);
         }
 
-        private SyntaxBase? ProcessCondition(JObject resource)
-        {
-            JProperty? conditionProperty = TemplateHelpers.GetProperty(resource, "condition");
-
-            if (conditionProperty == null)
-            {
-                return null;
-            }
-
-            SyntaxBase conditionExpression = ParseJToken(conditionProperty.Value);
-
-            if (conditionExpression is not ParenthesizedExpressionSyntax)
-            {
-                conditionExpression = new ParenthesizedExpressionSyntax(
-                    SyntaxHelpers.CreateToken(TokenType.LeftParen, "("),
-                    conditionExpression,
-                    SyntaxHelpers.CreateToken(TokenType.RightParen, ")"));
-            }
-
-            return new IfConditionSyntax(
-                SyntaxHelpers.CreateToken(TokenType.Identifier, "if"),
-                conditionExpression);
+        private SyntaxBase? ProcessCondition(JObject resource)
+        {
+            JProperty? conditionProperty = TemplateHelpers.GetProperty(resource, "condition");
+
+            if (conditionProperty == null)
+            {
+                return null;
+            }
+
+            SyntaxBase conditionExpression = ParseJToken(conditionProperty.Value);
+
+            if (conditionExpression is not ParenthesizedExpressionSyntax)
+            {
+                conditionExpression = new ParenthesizedExpressionSyntax(
+                    SyntaxHelpers.CreateToken(TokenType.LeftParen, "("),
+                    conditionExpression,
+                    SyntaxHelpers.CreateToken(TokenType.RightParen, ")"));
+            }
+
+            return new IfConditionSyntax(
+                SyntaxHelpers.CreateToken(TokenType.Identifier, "if"),
+                conditionExpression);
         }
 
         private SyntaxBase? ProcessDependsOn(JObject resource)
@@ -707,7 +707,7 @@ StringSyntax createFakeModulePath(string templateLinkExpression)
             return SyntaxHelpers.CreateArray(syntaxItems);
         }
 
-        private SyntaxBase? TryGetScopeProperty(JObject resource)
+        private SyntaxBase? TryModuleGetScopeProperty(JObject resource)
         {
             var subscriptionId = TemplateHelpers.GetProperty(resource, "subscriptionId");
             var resourceGroup = TemplateHelpers.GetProperty(resource, "resourceGroup");
@@ -789,7 +789,7 @@ private SyntaxBase ParseModule(JObject resource, string typeString, string nameS
             var properties = new List<ObjectPropertySyntax>();
             properties.Add(SyntaxHelpers.CreateObjectProperty("name", ParseJToken(nameString)));
 
-            var scope = TryGetScopeProperty(resource);
+            var scope = TryModuleGetScopeProperty(resource);
             if (scope is not null)
             {
                 properties.Add(SyntaxHelpers.CreateObjectProperty("scope", scope));
@@ -854,7 +854,28 @@ private SyntaxBase ParseModule(JObject resource, string typeString, string nameS
                 SyntaxHelpers.CreateObject(properties));
         }
 
-        public SyntaxBase ParseResource(JObject template, JToken value)
+        private SyntaxBase? TryGetResourceScopeProperty(JObject resource)
+        {
+            if (TemplateHelpers.GetProperty(resource, "scope") is not JProperty scopeProperty)
+            {
+                return null;
+            }
+
+            var scopeExpression = ExpressionHelpers.ParseExpression(scopeProperty.Value.Value<string>());
+            if (TryLookupResource(scopeExpression) is string resourceName)
+            {
+                return SyntaxHelpers.CreateIdentifier(resourceName);
+            }
+
+            if (TryParseStringExpression(scopeExpression) is SyntaxBase parsedSyntax)
+            {
+                return parsedSyntax;                    
+            }
+
+            throw new ConversionFailedException($"Parsing failed for property value {scopeProperty}", scopeProperty);
+        }
+
+        public SyntaxBase ParseResource(JToken value)
         {
             var resource = (value as JObject) ?? throw new ConversionFailedException($"Incorrect resource format", value);
 
@@ -886,6 +907,7 @@ public SyntaxBase ParseResource(JObject template, JToken value)
                 "properties",
                 "dependsOn",
                 "comments",
+                "scope",
             }, StringComparer.OrdinalIgnoreCase);
 
             var resourcePropsToOmit = new HashSet<string>(new [] {
@@ -894,10 +916,10 @@ public SyntaxBase ParseResource(JObject template, JToken value)
                 "apiVersion",
                 "dependsOn",
                 "comments",
+                "scope",
             }, StringComparer.OrdinalIgnoreCase);
 
             TemplateHelpers.AssertUnsupportedProperty(resource, "copy", "The 'copy' property is not supported");
-            TemplateHelpers.AssertUnsupportedProperty(resource, "scope", "The 'scope' property is not supported");
 
             var topLevelProperties = new List<ObjectPropertySyntax>();
             foreach (var prop in resource.Properties())
@@ -921,6 +943,12 @@ public SyntaxBase ParseResource(JObject template, JToken value)
                 topLevelProperties.Add(SyntaxHelpers.CreateObjectProperty(prop.Name, valueSyntax));
             }
 
+            var scope = TryGetResourceScopeProperty(resource);
+            if (scope is not null)
+            {
+                topLevelProperties.Add(SyntaxHelpers.CreateObjectProperty("scope", scope));
+            }
+
             var dependsOn = ProcessDependsOn(resource);
             if (dependsOn != null)
             {
@@ -1025,7 +1053,7 @@ private ProgramSyntax Parse()
 
             AddSyntaxBlock(statements, parameters.Select(ParseParam), false);
             AddSyntaxBlock(statements, variables.Select(ParseVariable), false);
-            AddSyntaxBlock(statements, flattenedResources.Select(r => ParseResource(template, r)), true);
+            AddSyntaxBlock(statements, flattenedResources.Select(ParseResource), true);
             AddSyntaxBlock(statements, outputs.Select(ParseOutput), false);
 
             return new ProgramSyntax(