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xy-sql-formatter

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Format whitespace in a SQL query to make it more readable

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import { isReserved, Token, TokenType } from './token.js'; /** * Ensures that no keyword token (RESERVED_*) is preceded or followed by a dot (.) * or any other property-access operator. * * Ensures that all RESERVED_FUNCTION_NAME tokens are followed by "(". * If they're not, converts the token to IDENTIFIER. * * Converts RESERVED_DATA_TYPE tokens followed by "(" to RESERVED_PARAMETERIZED_DATA_TYPE. * * When IDENTIFIER or RESERVED_DATA_TYPE token is followed by "[" * converts it to ARRAY_IDENTIFIER or ARRAY_KEYWORD accordingly. * * This is needed to avoid ambiguity in parser which expects function names * to always be followed by open-paren, and to distinguish between * array accessor `foo[1]` and array literal `[1, 2, 3]`. */ export function disambiguateTokens(tokens: Token[]): Token[] { return tokens .map(propertyNameKeywordToIdent) .map(funcNameToIdent) .map(dataTypeToParameterizedDataType) .map(identToArrayIdent) .map(dataTypeToArrayKeyword); } const propertyNameKeywordToIdent = (token: Token, i: number, tokens: Token[]): Token => { if (isReserved(token.type)) { const prevToken = prevNonCommentToken(tokens, i); if (prevToken && prevToken.type === TokenType.PROPERTY_ACCESS_OPERATOR) { return { ...token, type: TokenType.IDENTIFIER, text: token.raw }; } const nextToken = nextNonCommentToken(tokens, i); if (nextToken && nextToken.type === TokenType.PROPERTY_ACCESS_OPERATOR) { return { ...token, type: TokenType.IDENTIFIER, text: token.raw }; } } return token; }; const funcNameToIdent = (token: Token, i: number, tokens: Token[]): Token => { if (token.type === TokenType.RESERVED_FUNCTION_NAME) { const nextToken = nextNonCommentToken(tokens, i); if (!nextToken || !isOpenParen(nextToken)) { return { ...token, type: TokenType.IDENTIFIER, text: token.raw }; } } return token; }; const dataTypeToParameterizedDataType = (token: Token, i: number, tokens: Token[]): Token => { if (token.type === TokenType.RESERVED_DATA_TYPE) { const nextToken = nextNonCommentToken(tokens, i); if (nextToken && isOpenParen(nextToken)) { return { ...token, type: TokenType.RESERVED_PARAMETERIZED_DATA_TYPE }; } } return token; }; const identToArrayIdent = (token: Token, i: number, tokens: Token[]): Token => { if (token.type === TokenType.IDENTIFIER) { const nextToken = nextNonCommentToken(tokens, i); if (nextToken && isOpenBracket(nextToken)) { return { ...token, type: TokenType.ARRAY_IDENTIFIER }; } } return token; }; const dataTypeToArrayKeyword = (token: Token, i: number, tokens: Token[]): Token => { if (token.type === TokenType.RESERVED_DATA_TYPE) { const nextToken = nextNonCommentToken(tokens, i); if (nextToken && isOpenBracket(nextToken)) { return { ...token, type: TokenType.ARRAY_KEYWORD }; } } return token; }; const prevNonCommentToken = (tokens: Token[], index: number): Token | undefined => nextNonCommentToken(tokens, index, -1); const nextNonCommentToken = ( tokens: Token[], index: number, dir: -1 | 1 = 1 ): Token | undefined => { let i = 1; while (tokens[index + i * dir] && isComment(tokens[index + i * dir])) { i++; } return tokens[index + i * dir]; }; const isOpenParen = (t: Token): boolean => t.type === TokenType.OPEN_PAREN && t.text === '('; const isOpenBracket = (t: Token): boolean => t.type === TokenType.OPEN_PAREN && t.text === '['; const isComment = (t: Token): boolean => t.type === TokenType.BLOCK_COMMENT || t.type === TokenType.LINE_COMMENT;