Cannot get server to respond to Initialize request

[mtangoo]

I'm toying around LSP and I cannot get past first stage. Am using Python as client language since it is simple to work with. All I do is:

Connect to LSP - This works fine
Send Initialize JSON RPC - Client report success
Get response - Empty result

I have tried everything I could and read whatever I could find but I had no success. I hope for someone more conversant with LSP to help me pointing out what am doing wrong.

Here is the JSON

{
    "jsonrpc": "2.0",
    "id": 1,
    "method": " initialize",
    "params": {
        "processId": null,
        "rootPath": "/Users/stefano/Testing/PHPSources",
        "rootUri": "file:///Users/stefano/Testing/PHPSources",
        "capabilities": {
            "workspace": {
                "applyEdit": true,
                "workspaceEdit": {
                    "documentChanges": true,
                    "resourceOperations": [
                        "create",
                        "rename",
                        "delete"
                    ],
                    "failureHandling": "textOnlyTransactional"
                },
                "didChangeConfiguration": {
                    "dynamicRegistration": true
                },
                "didChangeWatchedFiles": {
                    "dynamicRegistration": true
                },
                "symbol": {
                    "dynamicRegistration": true,
                    "symbolKind": {
                        "valueSet": [
                            1,
                            2,
                            3,
                            4,
                            5,
                            6,
                            7,
                            8,
                            9,
                            10,
                            11,
                            12,
                            13,
                            14,
                            15,
                            16,
                            17,
                            18,
                            19,
                            20,
                            21,
                            22,
                            23,
                            24,
                            25,
                            26
                        ]
                    }
                },
                "executeCommand": {
                    "dynamicRegistration": true
                },
                "configuration": true,
                "workspaceFolders": true
            },
            "textDocument": {
                "publishDiagnostics": {
                    "relatedInformation": true,
                    "tagSupport": true
                },
                "synchronization": {
                    "dynamicRegistration": true,
                    "willSave": true,
                    "willSaveWaitUntil": true,
                    "didSave": true
                },
                "completion": {
                    "dynamicRegistration": true,
                    "contextSupport": true,
                    "completionItem": {
                        "snippetSupport": true,
                        "commitCharactersSupport": true,
                        "documentationFormat": [
                            "markdown",
                            "plaintext"
                        ],
                        "deprecatedSupport": true,
                        "preselectSupport": true
                    },
                    "completionItemKind": {
                        "valueSet": [
                            1,
                            2,
                            3,
                            4,
                            5,
                            6,
                            7,
                            8,
                            9,
                            10,
                            11,
                            12,
                            13,
                            14,
                            15,
                            16,
                            17,
                            18,
                            19,
                            20,
                            21,
                            22,
                            23,
                            24,
                            25
                        ]
                    }
                },
                "hover": {
                    "dynamicRegistration": true,
                    "contentFormat": [
                        "markdown",
                        "plaintext"
                    ]
                },
                "signatureHelp": {
                    "dynamicRegistration": true,
                    "signatureInformation": {
                        "documentationFormat": [
                            "markdown",
                            "plaintext"
                        ],
                        "parameterInformation": {
                            "labelOffsetSupport": true
                        }
                    }
                },
                "definition": {
                    "dynamicRegistration": true,
                    "linkSupport": true
                },
                "references": {
                    "dynamicRegistration": true
                },
                "documentHighlight": {
                    "dynamicRegistration": true
                },
                "documentSymbol": {
                    "dynamicRegistration": true,
                    "symbolKind": {
                        "valueSet": [
                            1,
                            2,
                            3,
                            4,
                            5,
                            6,
                            7,
                            8,
                            9,
                            10,
                            11,
                            12,
                            13,
                            14,
                            15,
                            16,
                            17,
                            18,
                            19,
                            20,
                            21,
                            22,
                            23,
                            24,
                            25,
                            26
                        ]
                    },
                    "hierarchicalDocumentSymbolSupport": true
                },
                "codeAction": {
                    "dynamicRegistration": true,
                    "codeActionLiteralSupport": {
                        "codeActionKind": {
                            "valueSet": [
                                "",
                                "quickfix",
                                "refactor",
                                "refactor.extract",
                                "refactor.inline",
                                "refactor.rewrite",
                                "source",
                                "source.organizeImports"
                            ]
                        }
                    }
                },
                "codeLens": {
                    "dynamicRegistration": true
                },
                "formatting": {
                    "dynamicRegistration": true
                },
                "rangeFormatting": {
                    "dynamicRegistration": true
                },
                "onTypeFormatting": {
                    "dynamicRegistration": true
                },
                "rename": {
                    "dynamicRegistration": true,
                    "prepareSupport": true
                },
                "documentLink": {
                    "dynamicRegistration": true
                },
                "typeDefinition": {
                    "dynamicRegistration": true,
                    "linkSupport": true
                },
                "implementation": {
                    "dynamicRegistration": true,
                    "linkSupport": true
                },
                "colorProvider": {
                    "dynamicRegistration": true
                },
                "foldingRange": {
                    "dynamicRegistration": true,
                    "rangeLimit": 5000,
                    "lineFoldingOnly": true
                },
                "declaration": {
                    "dynamicRegistration": true,
                    "linkSupport": true
                }
            }
        },
        "initializationOptions": {
            "storagePath": "/Users/hosanna/Library/Application Support/Code/User/workspaceStorage/30bd6a399166f4f329c9f383d63b74ca/bmewburn.vscode-intelephense-client",
            "clearCache": false
        },
        "trace": "verbose",
        "workspaceFolders": [
            {
                "uri": "file:///Users/stefano/Testing/PHPSources",
                "name": "TransportationApp"
            }
        ]
    }
}

Here is my full Python code. I tried with PHP Language Server but shouldn't matter the kind of server used.

import socket
import sys 

initReq = """
{
    "jsonrpc": "2.0",
    "id": 1,
    "method": " initialize",
    "params": {
        "processId": null,
        "rootPath": "/Users/stefano/Testing/PHPSources",
        "rootUri": "file:///Users/stefano/Testing/PHPSources",
        "capabilities": {
            "workspace": {
                "applyEdit": true,
                "workspaceEdit": {
                    "documentChanges": true,
                    "resourceOperations": [
                        "create",
                        "rename",
                        "delete"
                    ],
                    "failureHandling": "textOnlyTransactional"
                },
                "didChangeConfiguration": {
                    "dynamicRegistration": true
                },
                "didChangeWatchedFiles": {
                    "dynamicRegistration": true
                },
                "symbol": {
                    "dynamicRegistration": true,
                    "symbolKind": {
                        "valueSet": [
                            1,
                            2,
                            3,
                            4,
                            5,
                            6,
                            7,
                            8,
                            9,
                            10,
                            11,
                            12,
                            13,
                            14,
                            15,
                            16,
                            17,
                            18,
                            19,
                            20,
                            21,
                            22,
                            23,
                            24,
                            25,
                            26
                        ]
                    }
                },
                "executeCommand": {
                    "dynamicRegistration": true
                },
                "configuration": true,
                "workspaceFolders": true
            },
            "textDocument": {
                "publishDiagnostics": {
                    "relatedInformation": true,
                    "tagSupport": true
                },
                "synchronization": {
                    "dynamicRegistration": true,
                    "willSave": true,
                    "willSaveWaitUntil": true,
                    "didSave": true
                },
                "completion": {
                    "dynamicRegistration": true,
                    "contextSupport": true,
                    "completionItem": {
                        "snippetSupport": true,
                        "commitCharactersSupport": true,
                        "documentationFormat": [
                            "markdown",
                            "plaintext"
                        ],
                        "deprecatedSupport": true,
                        "preselectSupport": true
                    },
                    "completionItemKind": {
                        "valueSet": [
                            1,
                            2,
                            3,
                            4,
                            5,
                            6,
                            7,
                            8,
                            9,
                            10,
                            11,
                            12,
                            13,
                            14,
                            15,
                            16,
                            17,
                            18,
                            19,
                            20,
                            21,
                            22,
                            23,
                            24,
                            25
                        ]
                    }
                },
                "hover": {
                    "dynamicRegistration": true,
                    "contentFormat": [
                        "markdown",
                        "plaintext"
                    ]
                },
                "signatureHelp": {
                    "dynamicRegistration": true,
                    "signatureInformation": {
                        "documentationFormat": [
                            "markdown",
                            "plaintext"
                        ],
                        "parameterInformation": {
                            "labelOffsetSupport": true
                        }
                    }
                },
                "definition": {
                    "dynamicRegistration": true,
                    "linkSupport": true
                },
                "references": {
                    "dynamicRegistration": true
                },
                "documentHighlight": {
                    "dynamicRegistration": true
                },
                "documentSymbol": {
                    "dynamicRegistration": true,
                    "symbolKind": {
                        "valueSet": [
                            1,
                            2,
                            3,
                            4,
                            5,
                            6,
                            7,
                            8,
                            9,
                            10,
                            11,
                            12,
                            13,
                            14,
                            15,
                            16,
                            17,
                            18,
                            19,
                            20,
                            21,
                            22,
                            23,
                            24,
                            25,
                            26
                        ]
                    },
                    "hierarchicalDocumentSymbolSupport": true
                },
                "codeAction": {
                    "dynamicRegistration": true,
                    "codeActionLiteralSupport": {
                        "codeActionKind": {
                            "valueSet": [
                                "",
                                "quickfix",
                                "refactor",
                                "refactor.extract",
                                "refactor.inline",
                                "refactor.rewrite",
                                "source",
                                "source.organizeImports"
                            ]
                        }
                    }
                },
                "codeLens": {
                    "dynamicRegistration": true
                },
                "formatting": {
                    "dynamicRegistration": true
                },
                "rangeFormatting": {
                    "dynamicRegistration": true
                },
                "onTypeFormatting": {
                    "dynamicRegistration": true
                },
                "rename": {
                    "dynamicRegistration": true,
                    "prepareSupport": true
                },
                "documentLink": {
                    "dynamicRegistration": true
                },
                "typeDefinition": {
                    "dynamicRegistration": true,
                    "linkSupport": true
                },
                "implementation": {
                    "dynamicRegistration": true,
                    "linkSupport": true
                },
                "colorProvider": {
                    "dynamicRegistration": true
                },
                "foldingRange": {
                    "dynamicRegistration": true,
                    "rangeLimit": 5000,
                    "lineFoldingOnly": true
                },
                "declaration": {
                    "dynamicRegistration": true,
                    "linkSupport": true
                }
            }
        },
        "initializationOptions": {
            "storagePath": "/Users/hosanna/Library/Application Support/Code/User/workspaceStorage/30bd6a399166f4f329c9f383d63b74ca/bmewburn.vscode-intelephense-client",
            "clearCache": false
        },
        "trace": "verbose",
        "workspaceFolders": [
            {
                "uri": "file:///Users/stefano/Testing/PHPSources",
                "name": "TransportationApp"
            }
        ]
    }
}
"""

host = '127.0.0.1'
port = 8088

# create socket
print('# Creating socket')
try:
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
except socket.error:
    print('Failed to create socket')
    sys.exit()

# Connect to remote server
print('# Connecting to server, ' + host)
s.connect((host , port))

# Send data to remote server
print('# Sending data to server')

try:
    s.sendall(initReq.encode('utf-8'))
except socket.error:
    print('Send failed')
    sys.exit()

# Receive data
print('# Receive data from server')
reply = s.recv(4096)

print(reply) 

I apologize if the policy is for reporting bugs only here. I read some issues asking qustions, so I assumed I can ask questions here!

[rcjsuen]

@mtangoo I don't understand what you mean by:

Get response - Empty result

Did you send a request and the server sent you back an empty JSON or something? I suggest you show the exact output of everything in your Python script. I would also suggest truncating your code to not send such a big a payload to initialize. There's a lot of vertical scrolling involved here and the less you send the less variables you're including in your message (possibility for typos and so on).

In any case, from a cursory glance I get the feeling that your message isn't including a Content-Length header and all that good stuff.

The following is taken from the specification:

Content-Length: ...\r\n
\r\n
{
	"jsonrpc": "2.0",
	"id": 1,
	"method": "textDocument/didOpen",
	"params": {
		...
	}
}

[mtangoo]

Did you send a request and the server sent you back an empty JSON or something?

I mean the result of print is empty.

In any case, from a cursory glance I get the feeling that your message isn't including a Content-Length header and all that good stuff.
The following is taken from the specification:

Oh! my bad. How did I miss that? Let me add these and comment back

[mtangoo]

@rcjsuen that was it. I have added the header and all is well now. Thank you