snippet and inmemory uri support

[theprovenclub]

Hello eVeryone,

I am fairly new to language server world and have recently started configuring for one of my personal projects and need some help
I am running LSP(java command line) through a json rpc for websocket communication for my code editor.

i see there is a code in eclipse jdt github repo to support snippets and also inmemory uri but i can't seem to have it working through json request and response

I am using this version of LS
https://download.eclipse.org/jdtls/milestones/1.43.0/

Since the code will be written in code editor, so there is no actual file that will exist in the workspace

I tried enabling snippetSupport through below request but doesn;t seem to work. Any help would be appreciated!!

Request

{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "initialize",
    "params": {
        "processId": null,
        "rootUri": "inmemory://workspace",
        "capabilities": {
            "textDocument": {
                "completion": {
                    "completionItem": {
                        "snippetSupport": true
                    }
                }
            }
        }
    }
}

Response received

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "capabilities": {
      "textDocumentSync": {
        "openClose": true,
        "change": 2,
        "save": {
          "includeText": true
        }
      },
      "hoverProvider": true,
      "completionProvider": {
        "resolveProvider": true,
        "triggerCharacters": [
          ".",
          "@",
          "#",
          "*",
          " "
        ]
      },
      "signatureHelpProvider": {
        "triggerCharacters": [
          "(",
          ","
        ]
      },
      "definitionProvider": true,
      "typeDefinitionProvider": true,
      "implementationProvider": true,
      "referencesProvider": true,
      "documentHighlightProvider": true,
      "documentSymbolProvider": true,
      "workspaceSymbolProvider": true,
      "codeActionProvider": {
        "codeActionKinds": [],
        "resolveProvider": false
      },
      "codeLensProvider": {
        "resolveProvider": true
      },
      "documentFormattingProvider": true,
      "documentRangeFormattingProvider": true,
      "documentOnTypeFormattingProvider": {
        "firstTriggerCharacter": ";",
        "moreTriggerCharacter": [
          "\n",
          "}"
        ]
      },
      "renameProvider": {
        "prepareProvider": true
      },
      "foldingRangeProvider": true,
      "declarationProvider": true,
      "executeCommandProvider": {
        "commands": [
          "java.project.import",
          "java.project.changeImportedProjects",
          "java.navigate.openTypeHierarchy",
          "java.project.resolveStackTraceLocation",
          "java.edit.handlePasteEvent",
          "java.edit.stringFormatting",
          "java.project.getSettings",
          "java.project.resolveWorkspaceSymbol",
          "java.project.upgradeGradle",
          "java.project.createModuleInfo",
          "java.vm.getAllInstalls",
          "java.edit.organizeImports",
          "java.project.refreshDiagnostics",
          "java.project.removeFromSourcePath",
          "java.project.listSourcePaths",
          "java.project.updateSettings",
          "java.project.getAll",
          "java.reloadBundles",
          "java.project.isTestFile",
          "java.project.resolveText",
          "java.project.getClasspaths",
          "java.navigate.resolveTypeHierarchy",
          "java.edit.smartSemicolonDetection",
          "java.project.updateSourceAttachment",
          "java.project.updateClassPaths",
          "java.decompile",
          "java.protobuf.generateSources",
          "java.project.resolveSourceAttachment",
          "java.project.updateJdk",
          "java.project.addToSourcePath",
          "java.completion.onDidSelect"
        ]
      },
      "workspace": {
        "workspaceFolders": {
          "supported": true,
          "changeNotifications": true
        }
      },
      "typeHierarchyProvider": true,
      "callHierarchyProvider": true,
      "selectionRangeProvider": true,
      "semanticTokensProvider": {
        "legend": {
          "tokenTypes": [
            "namespace",
            "class",
            "interface",
            "enum",
            "enumMember",
            "type",
            "typeParameter",
            "method",
            "property",
            "variable",
            "parameter",
            "modifier",
            "keyword",
            "annotation",
            "annotationMember",
            "record",
            "recordComponent"
          ],
          "tokenModifiers": [
            "abstract",
            "static",
            "readonly",
            "deprecated",
            "declaration",
            "documentation",
            "public",
            "private",
            "protected",
            "native",
            "generic",
            "typeArgument",
            "importDeclaration",
            "constructor"
          ]
        },
        "range": false,
        "full": {
          "delta": false
        },
        "documentSelector": [
          {
            "language": "java",
            "scheme": "file"
          },
          {
            "language": "java",
            "scheme": "jdt"
          }
        ]
      },
      "inlayHintProvider": true
    }
  }
}

Also tried sending requests as below after initializing the capabilities

**didOpen request**
{
    "jsonrpc": "2.0",
    "method": "textDocument/didOpen",
    "params": {
        "textDocument": {
            "uri": "inmemory://workspace/Test.java",
            "languageId": "java",
            "version": 1,
            "text": "public class Test {\n    public static void main(String[] args) {\n        System.out.\n    }\n}"
        }
    }
}

**Completion request**
{
    "jsonrpc": "2.0",
    "id": 2,
    "method": "textDocument/completion",
    "params": {
        "textDocument": {
            "uri": "inmemory://workspace/Test.java"
        },
        "position": {
            "line": 2,
            "character": 17
        }
    }
}

Response i get is

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": {
    "isIncomplete": false,
    "items": []
  }
}

[fbricon]

Only file:// URIs are supported

[theprovenclub]

Thank you for the prompt response!
I have embedded a code editor in the browser and using in-memory - any suggestion on how can i handle this scenario.?

[rgrunber]

Looking through the JDT-LS codebase, I see places where we make assumptions regarding whether the file scheme is file (ie. file:/some/path/on/local/system). There's only a handful of these in the code base, but it would be good to examine them. Once that's solved, I think it should be possible to "teach" JDT-LS how to deal with your custom scheme (ie. inmemory). You could probably add your custom implementation in a separate bundle, and then just add that bundle to the runtime using the bundles initialization option.

JDT-LS deals with file because of definitions like :

https://github.com/eclipse-platform/eclipse.platform/blob/15f5d4e709350af206124bc184b70836e908f150/resources/bundles/org.eclipse.core.filesystem/plugin.xml#L5-L10
https://github.com/eclipse-platform/eclipse.platform/blob/15f5d4e709350af206124bc184b70836e908f150/resources/bundles/org.eclipse.core.filesystem/src/org/eclipse/core/internal/filesystem/local/LocalFileSystem.java

Most calls from the client end up needing to convert a URI to an IResource, and it happens at

eclipse.jdt.ls/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/JDTUtils.java

Lines 1120 to 1122 in 7d8b8b4

	public static IFile findFile(String uriString) {
	return (IFile) findResource(toURI(uriString), ResourcesPlugin.getWorkspace().getRoot()::findFilesForLocationURI);
	}

eclipse.jdt.ls/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/JDTUtils.java

Lines 1132 to 1134 in 7d8b8b4

	public static IContainer findFolder(String uriString) {
	return (IContainer) findResource(toURI(uriString), ResourcesPlugin.getWorkspace().getRoot()::findContainersForLocationURI);
	}

They lead to :

https://github.com/eclipse-platform/eclipse.platform/blob/15f5d4e709350af206124bc184b70836e908f150/resources/bundles/org.eclipse.core.filesystem/src/org/eclipse/core/internal/filesystem/InternalFileSystemCore.java#L127 .

And that's where the filesystem implementation needs to be defined.