planning

node_modules/graphql/language/experimentalOnlineParser/onlineParser.js.flow

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+// @flow strict
+import { Lexer } from '../lexer';
+import { Source } from '../source';
+
+import GraphQLGrammar from './grammar';
+import type {
+  GraphQLGrammarRule,
+  GraphQLGrammarRuleName,
+  GraphQLGrammarRuleConstraint,
+  GraphQLGrammarTokenConstraint,
+  GraphQLGrammarOfTypeConstraint,
+  GraphQLGrammarListOfTypeConstraint,
+  GraphQLGrammarPeekConstraint,
+  GraphQLGrammarConstraintsSet,
+} from './grammar';
+
+export const TokenKind = {
+  NAME: 'Name',
+  INT: 'Int',
+  FLOAT: 'Float',
+  STRING: 'String',
+  BLOCK_STRING: 'BlockString',
+  COMMENT: 'Comment',
+  PUNCTUATION: 'Punctuation',
+  EOF: '<EOF>',
+  INVALID: 'Invalid',
+};
+
+export const RuleKind = {
+  TOKEN_CONSTRAINT: 'TokenConstraint',
+  OF_TYPE_CONSTRAINT: 'OfTypeConstraint',
+  LIST_OF_TYPE_CONSTRAINT: 'ListOfTypeConstraint',
+  PEEK_CONSTRAINT: 'PeekConstraint',
+  CONSTRAINTS_SET: 'ConstraintsSet',
+  CONSTRAINTS_SET_ROOT: 'ConstraintsSetRoot',
+  RULE_NAME: 'RuleName',
+  INVALID: 'Invalid',
+};
+
+interface BaseOnlineParserRule {
+  kind: string;
+  name?: string;
+  depth: number;
+  step: number;
+  expanded: boolean;
+  state: string;
+  optional?: boolean;
+  eatNextOnFail?: boolean;
+}
+interface TokenOnlineParserRule
+  extends BaseOnlineParserRule,
+    GraphQLGrammarTokenConstraint {}
+interface OfTypeOnlineParserRule
+  extends BaseOnlineParserRule,
+    GraphQLGrammarOfTypeConstraint {}
+interface ListOfTypeOnlineParserRule
+  extends BaseOnlineParserRule,
+    GraphQLGrammarListOfTypeConstraint {}
+interface PeekOnlineParserRule
+  extends BaseOnlineParserRule,
+    GraphQLGrammarPeekConstraint {
+  index: number;
+  matched: boolean;
+}
+interface ConstraintsSetOnlineParserRule extends BaseOnlineParserRule {
+  constraintsSet: boolean;
+  constraints: GraphQLGrammarConstraintsSet;
+}
+
+type OnlineParserRule =
+  | TokenOnlineParserRule
+  | OfTypeOnlineParserRule
+  | ListOfTypeOnlineParserRule
+  | PeekOnlineParserRule
+  | ConstraintsSetOnlineParserRule;
+
+export type OnlineParserState = {|
+  rules: Array<OnlineParserRule>,
+  kind: () => string,
+  step: () => number,
+  levels: Array<number>,
+  indentLevel: number,
+  name: string | null,
+  type: string | null,
+|};
+
+type Token = {|
+  kind: string,
+  value: string,
+  tokenName?: ?string,
+  ruleName?: ?string,
+|};
+
+type LexerToken = {|
+  kind: string,
+  value: ?string,
+|};
+
+type OnlineParserConfig = {|
+  tabSize: number,
+|};
+
+type OnlineParserConfigOption = {|
+  tabSize: ?number,
+|};
+
+export class OnlineParser {
+  state: OnlineParserState;
+  _lexer: Lexer;
+  _config: OnlineParserConfig;
+
+  constructor(
+    source: string,
+    state?: OnlineParserState,
+    config?: OnlineParserConfigOption,
+  ) {
+    this.state = state || OnlineParser.startState();
+    this._config = {
+      tabSize: config?.tabSize ?? 2,
+    };
+    this._lexer = new Lexer(new Source(source));
+  }
+
+  static startState(): OnlineParserState {
+    return {
+      rules: [
+        // $FlowFixMe[cannot-spread-interface]
+        {
+          name: 'Document',
+          state: 'Document',
+          kind: 'ListOfTypeConstraint',
+          ...GraphQLGrammar.Document,
+          expanded: false,
+          depth: 1,
+          step: 1,
+        },
+      ],
+      name: null,
+      type: null,
+      levels: [],
+      indentLevel: 0,
+      kind(): string {
+        return this.rules[this.rules.length - 1]?.state || '';
+      },
+      step(): number {
+        return this.rules[this.rules.length - 1]?.step || 0;
+      },
+    };
+  }
+
+  static copyState(state: OnlineParserState): OnlineParserState {
+    return {
+      name: state.name,
+      type: state.type,
+      rules: JSON.parse(JSON.stringify(state.rules)),
+      levels: [...state.levels],
+      indentLevel: state.indentLevel,
+      kind(): string {
+        return this.rules[this.rules.length - 1]?.state || '';
+      },
+      step(): number {
+        return this.rules[this.rules.length - 1]?.step || 0;
+      },
+    };
+  }
+
+  sol(): boolean {
+    return (
+      this._lexer.source.locationOffset.line === 1 &&
+      this._lexer.source.locationOffset.column === 1
+    );
+  }
+
+  parseToken(): Token {
+    const rule = (this._getNextRule(): any);
+
+    if (this.sol()) {
+      this.state.indentLevel = Math.floor(
+        this.indentation() / this._config.tabSize,
+      );
+    }
+
+    if (!rule) {
+      return {
+        kind: TokenKind.INVALID,
+        value: '',
+      };
+    }
+
+    let token;
+
+    if (this._lookAhead().kind === '<EOF>') {
+      return {
+        kind: TokenKind.EOF,
+        value: '',
+        ruleName: rule.name,
+      };
+    }
+
+    switch (rule.kind) {
+      case RuleKind.TOKEN_CONSTRAINT:
+        token = this._parseTokenConstraint(rule);
+        break;
+      case RuleKind.LIST_OF_TYPE_CONSTRAINT:
+        token = this._parseListOfTypeConstraint(rule);
+        break;
+      case RuleKind.OF_TYPE_CONSTRAINT:
+        token = this._parseOfTypeConstraint(rule);
+        break;
+      case RuleKind.PEEK_CONSTRAINT:
+        token = this._parsePeekConstraint(rule);
+        break;
+      case RuleKind.CONSTRAINTS_SET_ROOT:
+        token = this._parseConstraintsSetRule(rule);
+        break;
+      default:
+        return {
+          kind: TokenKind.INVALID,
+          value: '',
+          ruleName: rule.name,
+        };
+    }
+
+    if (token && token.kind === TokenKind.INVALID) {
+      if (rule.optional === true) {
+        this.state.rules.pop();
+      } else {
+        this._rollbackRule();
+      }
+
+      return this.parseToken() || token;
+    }
+
+    return token;
+  }
+
+  indentation(): number {
+    const match = this._lexer.source.body.match(/\s*/);
+    let indent = 0;
+
+    if (match && match.length === 0) {
+      const whiteSpaces = match[0];
+      let pos = 0;
+      while (whiteSpaces.length > pos) {
+        if (whiteSpaces.charCodeAt(pos) === 9) {
+          indent += 2;
+        } else {
+          indent++;
+        }
+        pos++;
+      }
+    }
+
+    return indent;
+  }
+
+  _parseTokenConstraint(rule: TokenOnlineParserRule): Token {
+    rule.expanded = true;
+
+    const token = this._lookAhead();
+
+    if (!this._matchToken(token, rule)) {
+      return {
+        kind: TokenKind.INVALID,
+        value: '',
+        tokenName: rule.tokenName,
+        ruleName: rule.name,
+      };
+    }
+
+    this._advanceToken();
+    const parserToken = this._transformLexerToken(token, rule);
+    this._popMatchedRule(parserToken);
+
+    return parserToken;
+  }
+
+  _parseListOfTypeConstraint(rule: ListOfTypeOnlineParserRule): Token {
+    this._pushRule(
+      GraphQLGrammar[rule.listOfType],
+      rule.depth + 1,
+      rule.listOfType,
+      1,
+      rule.state,
+    );
+
+    rule.expanded = true;
+
+    const token = this.parseToken();
+
+    return token;
+  }
+
+  _parseOfTypeConstraint(rule: OfTypeOnlineParserRule): Token {
+    if (rule.expanded) {
+      this._popMatchedRule();
+      return this.parseToken();
+    }
+
+    this._pushRule(rule.ofType, rule.depth + 1, rule.tokenName, 1, rule.state);
+    rule.expanded = true;
+
+    const token = this.parseToken();
+
+    return token;
+  }
+
+  _parsePeekConstraint(rule: PeekOnlineParserRule): Token {
+    if (rule.expanded) {
+      this._popMatchedRule();
+      return this.parseToken();
+    }
+
+    while (!rule.matched && rule.index < rule.peek.length - 1) {
+      rule.index++;
+      const constraint = rule.peek[rule.index];
+
+      let { ifCondition } = constraint;
+      if (typeof ifCondition === 'string') {
+        ifCondition = GraphQLGrammar[ifCondition];
+      }
+
+      let token = this._lookAhead();
+      if (ifCondition && this._matchToken(token, ifCondition)) {
+        rule.matched = true;
+        rule.expanded = true;
+        this._pushRule(constraint.expect, rule.depth + 1, '', 1, rule.state);
+
+        token = this.parseToken();
+
+        return token;
+      }
+    }
+
+    return {
+      kind: TokenKind.INVALID,
+      value: '',
+      ruleName: rule.name,
+    };
+  }
+
+  _parseConstraintsSetRule(rule: ConstraintsSetOnlineParserRule): Token {
+    if (rule.expanded) {
+      this._popMatchedRule();
+      return this.parseToken();
+    }
+
+    for (let index = rule.constraints.length - 1; index >= 0; index--) {
+      this._pushRule(
+        rule.constraints[index],
+        rule.depth + 1,
+        '',
+        index,
+        rule.state,
+      );
+    }
+    rule.expanded = true;
+
+    return this.parseToken();
+  }
+
+  _matchToken(
+    token: Token | LexerToken,
+    rule: GraphQLGrammarTokenConstraint,
+  ): boolean {
+    if (typeof token.value === 'string') {
+      if (
+        (typeof rule.ofValue === 'string' && token.value !== rule.ofValue) ||
+        (Array.isArray(rule.oneOf) && !rule.oneOf.includes(token.value)) ||
+        (typeof rule.ofValue !== 'string' &&
+          !Array.isArray(rule.oneOf) &&
+          token.kind !== rule.token)
+      ) {
+        return false;
+      }
+
+      return this._butNot(token, rule);
+    }
+
+    if (token.kind !== rule.token) {
+      return false;
+    }
+
+    return this._butNot(token, rule);
+  }
+
+  _butNot(
+    token: Token | LexerToken,
+    rule: GraphQLGrammarRuleConstraint,
+  ): boolean {
+    if (rule.butNot) {
+      if (Array.isArray(rule.butNot)) {
+        if (
+          rule.butNot.reduce(
+            (matched, constraint) =>
+              matched || this._matchToken(token, constraint),
+            false,
+          )
+        ) {
+          return false;
+        }
+
+        return true;
+      }
+
+      return !this._matchToken(token, rule.butNot);
+    }
+
+    return true;
+  }
+
+  _transformLexerToken(lexerToken: LexerToken, rule: any): Token {
+    let token;
+    const ruleName = rule.name || '';
+    const tokenName = rule.tokenName || '';
+
+    if (lexerToken.kind === '<EOF>' || lexerToken.value !== undefined) {
+      token = {
+        kind: lexerToken.kind,
+        value: lexerToken.value || '',
+        tokenName,
+        ruleName,
+      };
+
+      if (token.kind === TokenKind.STRING) {
+        token.value = `"${token.value}"`;
+      } else if (token.kind === TokenKind.BLOCK_STRING) {
+        token.value = `"""${token.value}"""`;
+      }
+    } else {
+      token = {
+        kind: TokenKind.PUNCTUATION,
+        value: lexerToken.kind,
+        tokenName,
+        ruleName,
+      };
+
+      if (/^[{([]/.test(token.value)) {
+        if (this.state.indentLevel !== undefined) {
+          this.state.levels = this.state.levels.concat(
+            this.state.indentLevel + 1,
+          );
+        }
+      } else if (/^[})\]]/.test(token.value)) {
+        this.state.levels.pop();
+      }
+    }
+
+    return token;
+  }
+
+  _getNextRule(): OnlineParserRule | null {
+    return this.state.rules[this.state.rules.length - 1] || null;
+  }
+
+  _popMatchedRule(token: ?Token) {
+    const rule = this.state.rules.pop();
+    if (!rule) {
+      return;
+    }
+
+    if (token && rule.kind === RuleKind.TOKEN_CONSTRAINT) {
+      const constraint = rule;
+      if (typeof constraint.definitionName === 'string') {
+        this.state.name = token.value || null;
+      } else if (typeof constraint.typeName === 'string') {
+        this.state.type = token.value || null;
+      }
+    }
+
+    const nextRule = this._getNextRule();
+    if (!nextRule) {
+      return;
+    }
+
+    if (
+      nextRule.depth === rule.depth - 1 &&
+      nextRule.expanded &&
+      nextRule.kind === RuleKind.CONSTRAINTS_SET_ROOT
+    ) {
+      this.state.rules.pop();
+    }
+
+    if (
+      nextRule.depth === rule.depth - 1 &&
+      nextRule.expanded &&
+      nextRule.kind === RuleKind.LIST_OF_TYPE_CONSTRAINT
+    ) {
+      nextRule.expanded = false;
+      nextRule.optional = true;
+    }
+  }
+
+  _rollbackRule() {
+    if (!this.state.rules.length) {
+      return;
+    }
+
+    const popRule = () => {
+      const lastPoppedRule = this.state.rules.pop();
+
+      if (lastPoppedRule.eatNextOnFail === true) {
+        this.state.rules.pop();
+      }
+    };
+
+    const poppedRule = this.state.rules.pop();
+    if (!poppedRule) {
+      return;
+    }
+
+    let popped = 0;
+    let nextRule = this._getNextRule();
+    while (
+      nextRule &&
+      (poppedRule.kind !== RuleKind.LIST_OF_TYPE_CONSTRAINT ||
+        nextRule.expanded) &&
+      nextRule.depth > poppedRule.depth - 1
+    ) {
+      this.state.rules.pop();
+      popped++;
+      nextRule = this._getNextRule();
+    }
+
+    if (nextRule && nextRule.expanded) {
+      if (nextRule.optional === true) {
+        popRule();
+      } else {
+        if (
+          nextRule.kind === RuleKind.LIST_OF_TYPE_CONSTRAINT &&
+          popped === 1
+        ) {
+          this.state.rules.pop();
+          return;
+        }
+        this._rollbackRule();
+      }
+    }
+  }
+
+  _pushRule(
+    baseRule: any,
+    depth: number,
+    name?: string,
+    step?: number,
+    state?: string,
+  ) {
+    this.state.name = null;
+    this.state.type = null;
+    let rule = baseRule;
+
+    switch (this._getRuleKind(rule)) {
+      case RuleKind.RULE_NAME:
+        rule = (rule: GraphQLGrammarRuleName);
+        this._pushRule(
+          GraphQLGrammar[rule],
+          depth,
+          (typeof name === 'string' ? name : undefined) || rule,
+          step,
+          state,
+        );
+        break;
+      case RuleKind.CONSTRAINTS_SET:
+        rule = (rule: GraphQLGrammarConstraintsSet);
+        this.state.rules.push({
+          name: name || '',
+          depth,
+          expanded: false,
+          constraints: rule,
+          constraintsSet: true,
+          kind: RuleKind.CONSTRAINTS_SET_ROOT,
+          state:
+            (typeof name === 'string' ? name : undefined) ||
+            (typeof state === 'string' ? state : undefined) ||
+            this._getNextRule()?.state ||
+            '',
+          step:
+            typeof step === 'number'
+              ? step
+              : (this._getNextRule()?.step || 0) + 1,
+        });
+        break;
+      case RuleKind.OF_TYPE_CONSTRAINT:
+        rule = (rule: GraphQLGrammarOfTypeConstraint);
+        this.state.rules.push({
+          name: name || '',
+          ofType: rule.ofType,
+          optional: Boolean(rule.optional),
+          butNot: rule.butNot,
+          eatNextOnFail: Boolean(rule.eatNextOnFail),
+          depth,
+          expanded: false,
+          kind: RuleKind.OF_TYPE_CONSTRAINT,
+          state:
+            (typeof rule.tokenName === 'string' ? rule.tokenName : undefined) ||
+            (typeof name === 'string' ? name : undefined) ||
+            (typeof state === 'string' ? state : undefined) ||
+            this._getNextRule()?.state ||
+            '',
+          step:
+            typeof step === 'number'
+              ? step
+              : (this._getNextRule()?.step || 0) + 1,
+        });
+        break;
+      case RuleKind.LIST_OF_TYPE_CONSTRAINT:
+        rule = (rule: GraphQLGrammarListOfTypeConstraint);
+        this.state.rules.push({
+          listOfType: rule.listOfType,
+          optional: Boolean(rule.optional),
+          butNot: rule.butNot,
+          eatNextOnFail: Boolean(rule.eatNextOnFail),
+          name: name || '',
+          depth,
+          expanded: false,
+          kind: RuleKind.LIST_OF_TYPE_CONSTRAINT,
+          state:
+            (typeof name === 'string' ? name : undefined) ||
+            (typeof state === 'string' ? state : undefined) ||
+            this._getNextRule()?.state ||
+            '',
+          step:
+            typeof step === 'number'
+              ? step
+              : (this._getNextRule()?.step || 0) + 1,
+        });
+        break;
+      case RuleKind.TOKEN_CONSTRAINT:
+        rule = (rule: GraphQLGrammarTokenConstraint);
+        this.state.rules.push({
+          token: rule.token,
+          ofValue: rule.ofValue,
+          oneOf: rule.oneOf,
+          definitionName: Boolean(rule.definitionName),
+          typeName: Boolean(rule.typeName),
+          optional: Boolean(rule.optional),
+          butNot: rule.butNot,
+          eatNextOnFail: Boolean(rule.eatNextOnFail),
+          name: name || '',
+          depth,
+          expanded: false,
+          kind: RuleKind.TOKEN_CONSTRAINT,
+          state:
+            (typeof rule.tokenName === 'string' ? rule.tokenName : undefined) ||
+            (typeof state === 'string' ? state : undefined) ||
+            this._getNextRule()?.state ||
+            '',
+          step:
+            typeof step === 'number'
+              ? step
+              : (this._getNextRule()?.step || 0) + 1,
+        });
+        break;
+      case RuleKind.PEEK_CONSTRAINT:
+        rule = (rule: GraphQLGrammarPeekConstraint);
+        this.state.rules.push({
+          peek: rule.peek,
+          optional: Boolean(rule.optional),
+          butNot: rule.butNot,
+          eatNextOnFail: Boolean(rule.eatNextOnFail),
+          name: name || '',
+          depth,
+          index: -1,
+          matched: false,
+          expanded: false,
+          kind: RuleKind.PEEK_CONSTRAINT,
+          state:
+            (typeof state === 'string' ? state : undefined) ||
+            this._getNextRule()?.state ||
+            '',
+          step:
+            typeof step === 'number'
+              ? step
+              : (this._getNextRule()?.step || 0) + 1,
+        });
+        break;
+    }
+  }
+
+  _getRuleKind(rule: GraphQLGrammarRule | OnlineParserRule): string {
+    if (Array.isArray(rule)) {
+      return RuleKind.CONSTRAINTS_SET;
+    }
+
+    if (rule.constraintsSet === true) {
+      return RuleKind.CONSTRAINTS_SET_ROOT;
+    }
+
+    if (typeof rule === 'string') {
+      return RuleKind.RULE_NAME;
+    }
+
+    if (Object.prototype.hasOwnProperty.call(rule, 'ofType')) {
+      return RuleKind.OF_TYPE_CONSTRAINT;
+    }
+
+    if (Object.prototype.hasOwnProperty.call(rule, 'listOfType')) {
+      return RuleKind.LIST_OF_TYPE_CONSTRAINT;
+    }
+
+    if (Object.prototype.hasOwnProperty.call(rule, 'peek')) {
+      return RuleKind.PEEK_CONSTRAINT;
+    }
+
+    if (Object.prototype.hasOwnProperty.call(rule, 'token')) {
+      return RuleKind.TOKEN_CONSTRAINT;
+    }
+
+    return RuleKind.INVALID;
+  }
+
+  _advanceToken(): LexerToken {
+    return (this._lexer.advance(): any);
+  }
+
+  _lookAhead(): LexerToken {
+    try {
+      return (this._lexer.lookahead(): any);
+    } catch (err) {
+      return { kind: TokenKind.INVALID, value: '' };
+    }
+  }
+}