From 4ce47bb25077de87465cd54d4aa85cf3c8954d77 Mon Sep 17 00:00:00 2001
From: Naman Kumar <naman@outlook.in>
Date: Sun, 30 Aug 2020 20:48:42 +0530
Subject: [PATCH] [WIP] Integrate graphql-js experimental parser

---
 packages/codemirror-graphql/src/mode.js       | 20 ++---
 .../src/GraphqlParser.ts                      | 83 +++++++++++++++++++
 .../src/index.ts                              |  2 +
 3 files changed, 90 insertions(+), 15 deletions(-)
 create mode 100644 packages/graphql-language-service-parser/src/GraphqlParser.ts

diff --git a/packages/codemirror-graphql/src/mode.js b/packages/codemirror-graphql/src/mode.js
index 23dad24a13d..b9688341648 100644
--- a/packages/codemirror-graphql/src/mode.js
+++ b/packages/codemirror-graphql/src/mode.js
@@ -8,12 +8,7 @@
  */
 
 import CodeMirror from 'codemirror';
-import {
-  LexRules,
-  ParseRules,
-  isIgnored,
-  onlineParser,
-} from 'graphql-language-service-parser';
+import { GraphqlParser } from 'graphql-language-service-parser';
 
 /**
  * The GraphQL mode is defined as a tokenizer along with a list of rules, each
@@ -36,16 +31,11 @@ import {
  * which contains the relevant information to produce valuable typeaheads.
  */
 CodeMirror.defineMode('graphql', config => {
-  const parser = onlineParser({
-    eatWhitespace: stream => stream.eatWhile(isIgnored),
-    lexRules: LexRules,
-    parseRules: ParseRules,
-    editorConfig: { tabSize: config.tabSize },
-  });
+  const parser = new GraphqlParser({ tabSize: config.tabSize });
 
   return {
     config,
-    startState: parser.startState,
+    startState: GraphqlParser.startState,
     token: parser.token,
     indent,
     electricInput: /^\s*[})\]]/,
@@ -55,6 +45,7 @@ CodeMirror.defineMode('graphql', config => {
       pairs: '()[]{}""',
       explode: '()[]{}',
     },
+    copyState: GraphqlParser.copyState,
   };
 });
 
@@ -65,7 +56,6 @@ function indent(state, textAfter) {
   const level =
     !levels || levels.length === 0
       ? state.indentLevel
-      : levels[levels.length - 1] -
-        (this.electricInput.test(textAfter) ? 1 : 0);
+      : levels[levels.length - 1] - (this.electricInput.test(textAfter) ? 1 : 0);
   return level * this.config.indentUnit;
 }
diff --git a/packages/graphql-language-service-parser/src/GraphqlParser.ts b/packages/graphql-language-service-parser/src/GraphqlParser.ts
new file mode 100644
index 00000000000..50c14396aaa
--- /dev/null
+++ b/packages/graphql-language-service-parser/src/GraphqlParser.ts
@@ -0,0 +1,83 @@
+import { OnlineParser, OnlineParserState, TokenKind } from 'graphql/experimentalOnlineParser';
+import CharacterStream from './CharacterStream';
+import { isIgnored, LexRules } from './Rules';
+const styles = require('./styles.json');
+
+export interface State extends ParserState {
+  name: string | null;
+  type: string | null;
+  prevState: State | null;
+}
+
+export default class GraphqlParser {
+  config: any;
+
+  constructor(config = {}) {
+    this.config = config;
+  }
+
+  static startState = (): State => {
+    const state: any = OnlineParser.startState();
+    state.prevState = null;
+
+    return state;
+  };
+
+  static copyState = (state: State): State => {
+    const newState: any = OnlineParser.copyState(state);
+    newState.prevState = state.prevState;
+
+    return newState as State;
+  };
+
+  token(stream: CharacterStream, state: State): string {
+    const prevState = GraphqlParser.copyState(state);
+
+    if (stream.eatWhile(isIgnored)) {
+      return 'ws';
+    }
+
+    if (stream.eol()) {
+      return 'invalidchar';
+    }
+
+    const source = ((stream.match(/.*/, false) as Array<string>) || [])[0] || '';
+    const parserState = OnlineParser.copyState(state);
+    const parser = new OnlineParser(source, parserState, this.config);
+
+    const token = parser.parseToken();
+
+    if (token.kind !== 'Invalid' && token.value) {
+      Object.assign(state, parserState);
+      if (token.kind === TokenKind.PUNCTUATION) {
+        stream.match(LexRules.Punctuation);
+      } else {
+        stream.match(token.value);
+      }
+    } else {
+      stream.skipToEnd();
+    }
+
+    state.prevState = prevState;
+
+    return styles[token.tokenName] || styles[token.ruleName] || styles[token.kind] || '';
+  }
+}
+
+export type ContextToken = {
+  start: number;
+  end: number;
+  string: string;
+  state: State;
+  style: string;
+};
+
+export type ContextTokenForCodeMirror = {
+  start: number;
+  end: number;
+  string: string;
+  type: string | null;
+  state: State;
+};
+
+export type ContextTokenUnion = ContextToken | ContextTokenForCodeMirror;
diff --git a/packages/graphql-language-service-parser/src/index.ts b/packages/graphql-language-service-parser/src/index.ts
index 13c205c5571..d2ec818e7dd 100644
--- a/packages/graphql-language-service-parser/src/index.ts
+++ b/packages/graphql-language-service-parser/src/index.ts
@@ -15,4 +15,6 @@ export { butNot, list, opt, p, t } from './RuleHelpers';
 
 export { default as onlineParser } from './onlineParser';
 
+export { default as GraphqlParser } from './GraphqlParser';
+
 export * from './types';