Fixes for various minor decompiler issues (#5887)

* Fixes for issues 4896, 5881 & 5630

* Add repro for issue 2569

* Fix for issue 2162

* Add repro for issue 2639

* Fix for issue 2335

* Address PR comments

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

@@ -13,8 +13,8 @@ param FlowLogName string = 'FlowLog1'
 @description('Resource ID of the target NSG')
 param existingNSG string
 
+@description('Retention period in days. Default is zero which stands for permanent retention. Can be any Integer from 0 to 365')
 @metadata({
-  description: 'Retention period in days. Default is zero which stands for permanent retention. Can be any Integer from 0 to 365'
   range: 'From 0 to 365.'
 })
 @minValue(0)

src/Bicep.Decompiler.IntegrationTests/Working/issue2162/main.bicep

@@ -0,0 +1,8 @@
+resource foo 'Microsoft.Storage/storageAccounts@2021-01-01' = {
+  name: 'foo'
+  kind: 'StorageV2'
+  location: ''
+  sku: {
+    name: 'Standard_RAGRS'
+  }
+}

src/Bicep.Decompiler.IntegrationTests/Working/issue2162/main.json

@@ -0,0 +1,17 @@
+{
+    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
+    "contentVersion": "1.0.0.0",
+    "functions": [],
+    "resources": [
+        {
+            "type": "Microsoft.Storage/storageAccounts/",
+            "apiVersion": "2021-01-01",
+            "name": "foo",
+            "kind": "StorageV2",
+            "location": "",
+            "sku": {
+                "name": "Standard_RAGRS"
+            }
+        }
+    ]
+}

src/Bicep.Decompiler.IntegrationTests/Working/issue2335/main.bicep

@@ -0,0 +1 @@
+var foo = '{"fooKey": "bar"}'

src/Bicep.Decompiler.IntegrationTests/Working/issue2335/main.json

@@ -0,0 +1,7 @@
+{
+    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
+    "contentVersion": "1.0.0.0",
+    "variables": {
+        "foo": "[format('{{\"fooKey\": \"{0}\"}}', 'bar')]"
+    }
+}

src/Bicep.Decompiler.IntegrationTests/Working/issue2569/main.bicep

@@ -0,0 +1,4 @@
+param siteName string
+
+var apiSiteName = siteName
+var apiAppInsightsName = '${siteName}Insights'

src/Bicep.Decompiler.IntegrationTests/Working/issue2569/main.json

@@ -0,0 +1,13 @@
+{
+    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
+    "contentVersion": "1.0.0.0",
+    "parameters": {
+        "siteName": {
+            "type": "string"
+        }
+    },
+    "variables": {
+        "apiSiteName": "[concat(parameters('siteName'), '')]",
+        "apiAppInsightsName": "[concat(parameters('siteName'), 'Insights')]"
+    }
+}

src/Bicep.Decompiler.IntegrationTests/Working/issue2639/main.bicep

@@ -0,0 +1,26 @@
+param deployAutomationModules string
+param automationAccountName string
+param location string
+
+var automationModules = {
+  modules: [
+    {
+      Name: 'foo'
+      url: 'https://foo.com'
+    }
+  ]
+}
+
+resource automationAccountName_automationModules_modules_Name 'Microsoft.Automation/automationAccounts/modules@2015-10-31' = [for i in range(0, length(automationModules.modules)): if (deployAutomationModules == 'true') {
+  name: '${automationAccountName}/${automationModules.modules[i].Name}'
+  location: location
+  properties: {
+    contentLink: {
+      uri: automationModules.modules[i].url
+    }
+  }
+  dependsOn: [
+    resourceId('Microsoft.Automation/automationAccounts/', automationAccountName)
+//@[4:81) [BCP034 (Error)] The enclosing array expected an item of type "module[] | (resource | module) | resource[]", but the provided item was of type "string". (CodeDescription: none) |resourceId('Microsoft.Automation/automationAccounts/', automationAccountName)|
+  ]
+}]

src/Bicep.Decompiler.IntegrationTests/Working/issue2639/main.json

@@ -0,0 +1,46 @@
+{
+    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
+    "contentVersion": "1.0.0.0",
+    "parameters": {
+      "deployAutomationModules": {
+        "type": "string"
+      },
+      "automationAccountName": {
+        "type": "string"
+      },
+      "location": {
+        "type": "string"
+      }
+    },
+    "variables": {
+        "automationModules": {
+            "modules": [
+                {
+                    "Name": "foo",
+                    "url": "https://foo.com"
+                }
+            ]
+        }
+    },
+    "resources": [
+        {
+            "condition": "[equals(parameters('deployAutomationModules'),'true')]",
+            "apiVersion": "2015-10-31",
+            "type": "Microsoft.Automation/automationAccounts/modules",
+            "name": "[concat(parameters('automationAccountName'), '/', variables('automationModules').modules[copyIndex()].Name)]",
+            "location": "[parameters('location')]",
+            "dependsOn": [
+                "[resourceId('Microsoft.Automation/automationAccounts/', parameters('automationAccountName'))]"
+            ],
+            "copy": {
+                "name": "modulesLoop",
+                "count": "[length(variables('automationModules').modules)]"
+            },
+            "properties": {
+                "contentLink": {
+                    "uri": "[variables('automationModules').modules[copyIndex()].url]"
+                }
+            }
+        }
+    ]
+}

src/Bicep.Decompiler.IntegrationTests/Working/issue4896/main.bicep

@@ -0,0 +1,2 @@
+@description('The name of the Resource Group the VM(s) was/were created in.')
+output virtualMachinesResourceGroup string = resourceGroup().name

src/Bicep.Decompiler.IntegrationTests/Working/issue4896/main.json

@@ -0,0 +1,13 @@
+{
+    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
+    "contentVersion": "1.0.0.0",
+    "outputs": {
+        "virtualMachinesResourceGroup": {
+            "type": "string",
+            "value": "[resourceGroup().name]",
+            "metadata": {
+                "description": "The name of the Resource Group the VM(s) was/were created in."
+            }
+        }
+    }
+}

src/Bicep.Decompiler.IntegrationTests/Working/issue5881/main.bicep

@@ -0,0 +1,7 @@
+var foo = 'abc'
+var bar = guid(subscription().id, 'xxxx', foo)
+var abc = guid('blah')
+var def = {
+  '1234': '1234'
+  '${guid('blah')}': guid('blah')
+}

src/Bicep.Decompiler.IntegrationTests/Working/issue5881/main.json

@@ -0,0 +1,13 @@
+{
+    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
+    "contentVersion": "1.0.0.0",
+    "variables": {
+        "foo": "abc",
+        "bar": "[format('{0}', guid(subscription().id, 'xxxx', variables('foo')))]",
+        "abc": "[format('{0}', guid('blah'))]",
+        "def": {
+            "[format('{0}', 1234)]": "[format('{0}', 1234)]",
+            "[format('{0}', guid('blah'))]": "[format('{0}', guid('blah'))]"
+        }
+    }
+}

src/Bicep.Decompiler/ArmHelpers/ExpressionHelpers.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Text;
@@ -61,6 +62,32 @@ private static IEnumerable<LanguageExpression> CombineConcatArguments(IEnumerabl
             }
         }
 
+        private static ImmutableArray<(int index, int position, int length)> GetFormatStringHoles(string formatString)
+        {
+            var formatHoleMatches = Regex.Matches(formatString, "{([0-9]+)}");
+            var formatHoles = formatHoleMatches
+                .Select(match => (
+                    index: int.Parse(match.Groups[1].Value),
+                    position: match.Groups[1].Index,
+                    length: match.Groups[1].Length
+                ));
+
+            return formatHoles.ToImmutableArray();
+        }
+
+        private static string UnescapeFormatString(string formatString)
+        {
+            var formatHoles = GetFormatStringHoles(formatString);
+
+            var maxIndex = formatHoles.Select(x => x.index).Aggregate(Math.Max);
+            var replacements = Enumerable.Range(0, maxIndex + 1).Select(index => $"{{{index}}}");
+
+            // Use string.Format to handle unescaping for us - by passing "{index}" for each hole.
+            // This will replace '{{' and '}}' with '{' and '}' as appropriate.
+            // This works because the deployment engine format uses the same algorithm (string.Format) to handle replacement.
+            return String.Format(formatString, replacements.ToArray());
+        }
+
         public static LanguageExpression FlattenStringOperations(LanguageExpression original)
         {
             if (original is not FunctionExpression functionExpression)
@@ -72,17 +99,14 @@ public static LanguageExpression FlattenStringOperations(LanguageExpression orig
             if (functionExpression.NameEquals("format"))
             {
                 var formatString = (functionExpression.Parameters[0] as JTokenExpression)?.Value.Value<string>() ?? throw new ArgumentException($"Unable to read format statement {ExpressionsEngine.SerializeExpression(functionExpression)} as string");
-                var formatHoleMatches = Regex.Matches(formatString, "{([0-9]+)}");
+                formatString = UnescapeFormatString(formatString);
+
+                var formatHoles = GetFormatStringHoles(formatString);
 
                 var concatExpressions = new List<LanguageExpression>();
                 var nextStart = 0;
-                for (var i = 0; i < formatHoleMatches.Count; i++)
+                foreach (var (index, position, length) in formatHoles)
                 {
-                    var match = formatHoleMatches[i];
-                    var position = match.Groups[1].Index;
-                    var length = match.Groups[1].Length;
-                    var intValue = int.Parse(match.Groups[1].Value);
-
                     // compensate for the {
                     if (nextStart < position - 1)
                     {
@@ -91,7 +115,7 @@ public static LanguageExpression FlattenStringOperations(LanguageExpression orig
                     }
 
                     // replace it with the appropriately-numbered expression
-                    concatExpressions.Add(functionExpression.Parameters[intValue + 1]);
+                    concatExpressions.Add(functionExpression.Parameters[index + 1]);
 
                     // compensate for the }
                     nextStart = position + length + 1;

src/Bicep.Decompiler/ArmHelpers/TemplateHelpers.cs

@@ -70,7 +70,7 @@ public static JToken AssertRequiredProperty(JObject parent, string propertyName,
 
         public static (string type, string name, string apiVersion) ParseResource(JObject resource)
         {
-            var type = AssertRequiredProperty(resource, "type", $"Unable to parse \"type\" for resource").ToString();
+            var type = AssertRequiredProperty(resource, "type", $"Unable to parse \"type\" for resource").ToString().Trim('/');
             var name = AssertRequiredProperty(resource, "name", $"Unable to parse \"name\" for resource").ToString();
             var apiVersion = AssertRequiredProperty(resource, "apiVersion", $"Unable to parse \"apiVersion\" for resource").ToString();