Add json spec

Author: octref

README.md

@@ -12,9 +12,9 @@ Try it at https://microsoft.github.io/language-server-protocol/inspector/.
 
 ## Motivation
 
-When you are using [vscode-languageserver-node](https://github.com/Microsoft/vscode-languageserver-node) to develop a language server, it's possible to specify a setting `"[langId]".trace.server: "verbose"` to make the Language Client log the LSP communication. This log is useful for developing and testing the Language Server, but the log can be lengthy — 5 seconds of usage might generate 5000 lines LSP log. This makes it hard to gain insight from the logs.
+When you are using [vscode-languageserver-node](https://github.com/Microsoft/vscode-languageserver-node) to develop a language server, it's possible to specify a setting `"[langId].trace.server": "verbose"` to make the Language Client log the LSP communication. This log is useful for developing and testing the Language Server, but the log can be lengthy — using the editor for 5 seconds could generate 5000 lines of LSP log. This makes it hard to gain insight from the logs.
 
-This inspector visualizes the logs to make it easy to understand the communication between the Language Client / Server. It also lets you filter down the logs by search query or language features, so you can quickly identify the logs you are interested in.
+This inspector visualizes the logs to make it easy to understand the communication between the Language Client / Server. It also lets you filter the logs by search query or language features, so you can quickly identify the logs you are interested in.
 
 ![lsp-inspector](https://user-images.githubusercontent.com/4033249/41323525-ba73697a-6e63-11e8-92a3-c655b34126f6.gif)
 
@@ -31,6 +31,43 @@ This inspector visualizes the logs to make it easy to understand the communicati
   - Load it from the web app.
 - You can try it on real-world logs file at `/tests/unit/logParser/fixture`.
 
+## Log Format
+
+The Inspector takes two log formats: `Text` and `JSON`.
+
+- `Text`:
+  - Logs generated by setting `"[langId].trace.server": "verbose"`.
+  - Logs generated by setting `"[langId].trace.server": { "format": "Text" }`
+- `JSON`: Logs generated by setting: `"[langId].trace.server": { "format": "JSON" }`
+
+The Inspector could load any JSON logs, as long as they follow this format:
+
+```ts
+export type MsgKind =
+  | 'send-notification'
+  | 'recv-notification'
+  | 'send-request'
+  | 'recv-request'
+  | 'send-response'
+  | 'recv-response'
+
+export interface LspItem {
+  type: MsgKind
+  message: any
+  timestamp: unix timestamp
+}
+
+```
+
+Each line is terminated with `\r\n`.
+
+Here is a sample:
+
+```
+{"type":"receive-response","message":{"jsonrpc":"2.0","id":0,"result":{"capabilities":{"textDocumentSync":1,"completionProvider":{"resolveProvider":true}}}},"timestamp":1534721620392}\r\n
+{"type":"send-notification","message":{"jsonrpc":"2.0","method":"initialized","params":{}},"timestamp":1534721620393}\r\n
+```
+
 ## Running & Developing
 
 - `yarn`