Add completion for nested resources

src/Bicep.Core.Samples/Files/InvalidResources_CRLF/Completions/deploymentScriptTopLevel.json

@@ -83,6 +83,56 @@
       ":"
     ]
   },
+  {
+    "label": "resource",
+    "kind": "keyword",
+    "detail": "Resource keyword",
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "plainText",
+    "insertTextMode": "asIs",
+    "textEdit": {
+      "range": {},
+      "newText": "resource"
+    }
+  },
+  {
+    "label": "resource",
+    "kind": "snippet",
+    "detail": "Nested resource with defaults",
+    "documentation": {
+      "kind": "markdown",
+      "value": "```bicep\nresource Identifier 'Type' = {\n  name: \n  properties: {\n    \n  }\n}\n```"
+    },
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "snippet",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "resource ${1:Identifier} '${2:Type}' = {\n  name: $3\n  properties: {\n    $0\n  }\n}"
+    }
+  },
+  {
+    "label": "resource",
+    "kind": "snippet",
+    "detail": "Nested resource without defaults",
+    "documentation": {
+      "kind": "markdown",
+      "value": "```bicep\nresource Identifier 'Type' = {\n  name: \n  \n}\n\n```"
+    },
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "snippet",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "resource ${1:Identifier} '${2:Type}' = {\n  name: $3\n  $0\n}\n"
+    }
+  },
   {
     "label": "tags",
     "kind": "property",

src/Bicep.Core.Samples/Files/InvalidResources_CRLF/Completions/discriminatorProperty.json

@@ -19,5 +19,55 @@
     "commitCharacters": [
       ":"
     ]
+  },
+  {
+    "label": "resource",
+    "kind": "keyword",
+    "detail": "Resource keyword",
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "plainText",
+    "insertTextMode": "asIs",
+    "textEdit": {
+      "range": {},
+      "newText": "resource"
+    }
+  },
+  {
+    "label": "resource",
+    "kind": "snippet",
+    "detail": "Nested resource with defaults",
+    "documentation": {
+      "kind": "markdown",
+      "value": "```bicep\nresource Identifier 'Type' = {\n  name: \n  properties: {\n    \n  }\n}\n```"
+    },
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "snippet",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "resource ${1:Identifier} '${2:Type}' = {\n  name: $3\n  properties: {\n    $0\n  }\n}"
+    }
+  },
+  {
+    "label": "resource",
+    "kind": "snippet",
+    "detail": "Nested resource without defaults",
+    "documentation": {
+      "kind": "markdown",
+      "value": "```bicep\nresource Identifier 'Type' = {\n  name: \n  \n}\n\n```"
+    },
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "snippet",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "resource ${1:Identifier} '${2:Type}' = {\n  name: $3\n  $0\n}\n"
+    }
   }
 ]

src/Bicep.Core.Samples/Files/InvalidResources_CRLF/Completions/topLevelProperties.json

@@ -146,6 +146,56 @@
       ":"
     ]
   },
+  {
+    "label": "resource",
+    "kind": "keyword",
+    "detail": "Resource keyword",
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "plainText",
+    "insertTextMode": "asIs",
+    "textEdit": {
+      "range": {},
+      "newText": "resource"
+    }
+  },
+  {
+    "label": "resource",
+    "kind": "snippet",
+    "detail": "Nested resource with defaults",
+    "documentation": {
+      "kind": "markdown",
+      "value": "```bicep\nresource Identifier 'Type' = {\n  name: \n  properties: {\n    \n  }\n}\n```"
+    },
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "snippet",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "resource ${1:Identifier} '${2:Type}' = {\n  name: $3\n  properties: {\n    $0\n  }\n}"
+    }
+  },
+  {
+    "label": "resource",
+    "kind": "snippet",
+    "detail": "Nested resource without defaults",
+    "documentation": {
+      "kind": "markdown",
+      "value": "```bicep\nresource Identifier 'Type' = {\n  name: \n  \n}\n\n```"
+    },
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "snippet",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "resource ${1:Identifier} '${2:Type}' = {\n  name: $3\n  $0\n}\n"
+    }
+  },
   {
     "label": "sku",
     "kind": "property",

src/Bicep.Core.Samples/Files/InvalidResources_CRLF/Completions/topLevelPropertiesMinusName.json

@@ -125,6 +125,56 @@
       ":"
     ]
   },
+  {
+    "label": "resource",
+    "kind": "keyword",
+    "detail": "Resource keyword",
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "plainText",
+    "insertTextMode": "asIs",
+    "textEdit": {
+      "range": {},
+      "newText": "resource"
+    }
+  },
+  {
+    "label": "resource",
+    "kind": "snippet",
+    "detail": "Nested resource with defaults",
+    "documentation": {
+      "kind": "markdown",
+      "value": "```bicep\nresource Identifier 'Type' = {\n  name: \n  properties: {\n    \n  }\n}\n```"
+    },
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "snippet",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "resource ${1:Identifier} '${2:Type}' = {\n  name: $3\n  properties: {\n    $0\n  }\n}"
+    }
+  },
+  {
+    "label": "resource",
+    "kind": "snippet",
+    "detail": "Nested resource without defaults",
+    "documentation": {
+      "kind": "markdown",
+      "value": "```bicep\nresource Identifier 'Type' = {\n  name: \n  \n}\n\n```"
+    },
+    "deprecated": false,
+    "preselect": false,
+    "sortText": "2_resource",
+    "insertTextFormat": "snippet",
+    "insertTextMode": "adjustIndentation",
+    "textEdit": {
+      "range": {},
+      "newText": "resource ${1:Identifier} '${2:Type}' = {\n  name: $3\n  $0\n}\n"
+    }
+  },
   {
     "label": "sku",
     "kind": "property",

src/Bicep.LangServer/Completions/BicepCompletionContext.cs

@@ -106,11 +106,12 @@ public static BicepCompletionContext Create(Compilation compilation, int offset)
             var activeScopes = ActiveScopesVisitor.GetActiveScopes(compilation.GetEntrypointSemanticModel().Root, offset);
 
             var kind = ConvertFlag(IsTopLevelDeclarationStartContext(matchingNodes, offset), BicepCompletionContextKind.TopLevelDeclarationStart) |
+                       ConvertFlag(IsNestedResourceStartContext(matchingNodes, topLevelDeclarationInfo, objectInfo, offset), BicepCompletionContextKind.NestedResourceDeclarationStart) |
                        GetDeclarationTypeFlags(matchingNodes, offset) |
                        ConvertFlag(IsObjectPropertyNameContext(matchingNodes, objectInfo), BicepCompletionContextKind.ObjectPropertyName) |
                        ConvertFlag(IsMemberAccessContext(matchingNodes, propertyAccessInfo, offset), BicepCompletionContextKind.MemberAccess) |
                        ConvertFlag(IsResourceAccessContext(matchingNodes, resourceAccessInfo, offset), BicepCompletionContextKind.ResourceAccess) |
-                       ConvertFlag(IsArrayIndexContext(matchingNodes,arrayAccessInfo), BicepCompletionContextKind.ArrayIndex | BicepCompletionContextKind.Expression) |
+                       ConvertFlag(IsArrayIndexContext(matchingNodes, arrayAccessInfo), BicepCompletionContextKind.ArrayIndex | BicepCompletionContextKind.Expression) |
                        ConvertFlag(IsPropertyValueContext(matchingNodes, propertyInfo), BicepCompletionContextKind.PropertyValue | BicepCompletionContextKind.Expression) |
                        ConvertFlag(IsArrayItemContext(matchingNodes, arrayInfo), BicepCompletionContextKind.ArrayItem | BicepCompletionContextKind.Expression) |
                        ConvertFlag(IsResourceBodyContext(matchingNodes, offset), BicepCompletionContextKind.ResourceBody) |
@@ -258,6 +259,57 @@ private static bool IsTopLevelDeclarationStartContext(List<SyntaxBase> matchingN
             return false;
         }
 
+        private static bool IsNestedResourceStartContext(List<SyntaxBase> matchingNodes, (SyntaxBase? node, int index) topLevelDeclarationInfo, (ObjectSyntax? node, int index) objectInfo, int offset)
+        {
+            // A nested resource must be at the top level of a resource declaration (not nested within another level of object).
+            if (objectInfo.node == null)
+            {
+                // none of the matching nodes are ObjectSyntax,
+                // so we cannot possibly be in a position to begin an object property
+                return false;
+            }
+
+            if (topLevelDeclarationInfo.node == null || topLevelDeclarationInfo.node is not ResourceDeclarationSyntax resourceDeclarationSyntax)
+            {
+                // not inside of a resource, top level declarations are handled separately.
+                return false;
+            }
+
+            if (!object.ReferenceEquals(resourceDeclarationSyntax.TryGetBody(), objectInfo.node))
+            {
+                // we're inside of an object, but it's not the body of a resource.
+                return false;
+            }
+
+            switch (matchingNodes[^1])
+            {
+                case ObjectSyntax _:
+                    // we are somewhere in the trivia portion of the object node (trivia span is not included in the token span)
+                    // which is why the last node in the list of matching nodes is not a Token.
+                    return true;
+
+                case Token token:
+                    int nodeCount = matchingNodes.Count - objectInfo.index;
+
+                    switch (nodeCount)
+                    {
+                        case 2 when token.Type == TokenType.NewLine:
+                            return true;
+
+                        case 4 when matchingNodes[^2] is IdentifierSyntax identifier && matchingNodes[^3] is ObjectPropertySyntax property && ReferenceEquals(property.Key, identifier):
+                            // we are in a partial or full property name 
+                            return true;
+
+                        case 4 when matchingNodes[^2] is SkippedTriviaSyntax skipped && matchingNodes[^3] is ObjectPropertySyntax property && ReferenceEquals(property.Key, skipped):
+                            return true;
+                    }
+
+                    break;
+            }
+
+            return false;
+        }
+
         private static bool IsMemberAccessContext(List<SyntaxBase> matchingNodes, (PropertyAccessSyntax? node, int index) propertyAccessInfo, int offset)
         {
             return propertyAccessInfo.node != null &&

src/Bicep.LangServer/Completions/BicepCompletionContextKind.cs

@@ -92,6 +92,9 @@ public enum BicepCompletionContextKind
         /// </summary>
         DecoratorName = 1 << 15,
 
-
+        /// <summary>
+        /// The current location could be the start of a nested resource declaration.
+        /// </summary>
+        NestedResourceDeclarationStart = 1 << 16,
     }
 }

src/Bicep.LangServer/Completions/BicepCompletionProvider.cs

@@ -114,6 +114,25 @@ private IEnumerable<CompletionItem> GetDeclarationCompletions(BicepCompletionCon
 
                 yield return CreateKeywordCompletion(LanguageConstants.TargetScopeKeyword, "Target Scope keyword", context.ReplacementRange);
             }
+
+            if (context.Kind.HasFlag(BicepCompletionContextKind.NestedResourceDeclarationStart))
+            {
+                yield return CreateKeywordCompletion(LanguageConstants.ResourceKeyword, "Resource keyword", context.ReplacementRange);
+
+                // leaving out the API version on this, because we expect its more common to inherit from the containing resource.
+                yield return CreateContextualSnippetCompletion(LanguageConstants.ResourceKeyword, "Nested resource with defaults", @"resource ${1:Identifier} '${2:Type}' = {
+  name: $3
+  properties: {
+    $0
+  }
+}", context.ReplacementRange, insertTextMode: InsertTextMode.AdjustIndentation);
+
+                yield return CreateContextualSnippetCompletion(LanguageConstants.ResourceKeyword, "Nested resource without defaults", @"resource ${1:Identifier} '${2:Type}' = {
+  name: $3
+  $0
+}
+", context.ReplacementRange, insertTextMode: InsertTextMode.AdjustIndentation);
+            }
         }
 
         private IEnumerable<CompletionItem> GetTargetScopeCompletions(SemanticModel model, BicepCompletionContext context)