feat(encoding/csv): sync parse (#2491)

Author: timreichen

encoding/csv.ts

@@ -2,24 +2,18 @@
 // https://github.com/golang/go/blob/master/LICENSE
 // Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
 
+// This module is browser compatible.
+
 /** Port of the Go
  * [encoding/csv](https://github.com/golang/go/blob/go1.12.5/src/encoding/csv/)
  * library.
  *
  * @module
  */
 
-import { BufReader } from "../io/buffer.ts";
-import { TextProtoReader } from "../textproto/mod.ts";
-import { StringReader } from "../io/readers.ts";
 import { assert } from "../_util/assert.ts";
-import {
-  ERR_FIELD_COUNT,
-  ERR_INVALID_DELIM,
-  ParseError,
-  readRecord,
-} from "./csv/_io.ts";
-import type { LineReader, ReadOptions } from "./csv/_io.ts";
+import type { ReadOptions } from "./csv/_io.ts";
+import { Parser } from "./csv/_parser.ts";
 
 export {
   ERR_BARE_QUOTE,
@@ -38,111 +32,6 @@ export type {
   StringifyOptions,
 } from "./csv_stringify.ts";
 
-class TextProtoLineReader implements LineReader {
-  #tp: TextProtoReader;
-  constructor(bufReader: BufReader) {
-    this.#tp = new TextProtoReader(bufReader);
-  }
-
-  async readLine() {
-    let line: string;
-    const r = await this.#tp.readLine();
-    if (r === null) return null;
-    line = r;
-
-    // For backwards compatibility, drop trailing \r before EOF.
-    if (
-      (await this.isEOF()) && line.length > 0 && line[line.length - 1] === "\r"
-    ) {
-      line = line.substring(0, line.length - 1);
-    }
-
-    // Normalize \r\n to \n on all input lines.
-    if (
-      line.length >= 2 &&
-      line[line.length - 2] === "\r" &&
-      line[line.length - 1] === "\n"
-    ) {
-      line = line.substring(0, line.length - 2);
-      line = line + "\n";
-    }
-
-    return line;
-  }
-
-  async isEOF() {
-    return (await this.#tp.r.peek(0)) === null;
-  }
-}
-
-const INVALID_RUNE = ["\r", "\n", '"'];
-
-function chkOptions(opt: ReadOptions): void {
-  if (!opt.separator) {
-    opt.separator = ",";
-  }
-  if (!opt.trimLeadingSpace) {
-    opt.trimLeadingSpace = false;
-  }
-  if (
-    INVALID_RUNE.includes(opt.separator) ||
-    (typeof opt.comment === "string" && INVALID_RUNE.includes(opt.comment)) ||
-    opt.separator === opt.comment
-  ) {
-    throw new Error(ERR_INVALID_DELIM);
-  }
-}
-
-/**
- * Parse the CSV from the `reader` with the options provided and return `string[][]`.
- *
- * @param reader provides the CSV data to parse
- * @param opt controls the parsing behavior
- */
-export async function readMatrix(
-  reader: BufReader,
-  opt: ReadOptions = {
-    separator: ",",
-    trimLeadingSpace: false,
-    lazyQuotes: false,
-  },
-): Promise<string[][]> {
-  const result: string[][] = [];
-  let _nbFields: number | undefined;
-  let lineResult: string[];
-  let first = true;
-  let lineIndex = 0;
-  chkOptions(opt);
-
-  const lineReader = new TextProtoLineReader(reader);
-  for (;;) {
-    const r = await readRecord(lineIndex, lineReader, opt);
-    if (r === null) break;
-    lineResult = r;
-    lineIndex++;
-    // If fieldsPerRecord is 0, Read sets it to
-    // the number of fields in the first record
-    if (first) {
-      first = false;
-      if (opt.fieldsPerRecord !== undefined) {
-        if (opt.fieldsPerRecord === 0) {
-          _nbFields = lineResult.length;
-        } else {
-          _nbFields = opt.fieldsPerRecord;
-        }
-      }
-    }
-
-    if (lineResult.length > 0) {
-      if (_nbFields && _nbFields !== lineResult.length) {
-        throw new ParseError(lineIndex, lineIndex, null, ERR_FIELD_COUNT);
-      }
-      result.push(lineResult);
-    }
-  }
-  return result;
-}
-
 /**
  * Parse the CSV string/buffer with the options provided.
  *
@@ -173,46 +62,43 @@ export interface ParseOptions extends ReadOptions {
 /**
  * Csv parse helper to manipulate data.
  * Provides an auto/custom mapper for columns.
- * @param input Input to parse. Can be a string or BufReader.
+ * @param input Input to parse.
  * @param opt options of the parser.
  * @returns If you don't provide `opt.skipFirstRow` and `opt.columns`, it returns `string[][]`.
  *   If you provide `opt.skipFirstRow` or `opt.columns`, it returns `Record<string, unkown>[]`.
  */
-export async function parse(
-  input: string | BufReader,
-): Promise<string[][]>;
-export async function parse(
-  input: string | BufReader,
+export function parse(
+  input: string,
+): string[][];
+export function parse(
+  input: string,
   opt: Omit<ParseOptions, "columns" | "skipFirstRow">,
-): Promise<string[][]>;
-export async function parse(
-  input: string | BufReader,
+): string[][];
+export function parse(
+  input: string,
   opt: Omit<ParseOptions, "columns"> & {
     columns: string[] | ColumnOptions[];
   },
-): Promise<Record<string, unknown>[]>;
-export async function parse(
-  input: string | BufReader,
+): Record<string, unknown>[];
+export function parse(
+  input: string,
   opt: Omit<ParseOptions, "skipFirstRow"> & {
     skipFirstRow: true;
   },
-): Promise<Record<string, unknown>[]>;
-export async function parse(
-  input: string | BufReader,
+): Record<string, unknown>[];
+export function parse(
+  input: string,
   opt: ParseOptions,
-): Promise<string[][] | Record<string, unknown>[]>;
-export async function parse(
-  input: string | BufReader,
+): string[][] | Record<string, unknown>[];
+export function parse(
+  input: string,
   opt: ParseOptions = {
     skipFirstRow: false,
   },
-): Promise<string[][] | Record<string, unknown>[]> {
-  let r: string[][];
-  if (input instanceof BufReader) {
-    r = await readMatrix(input, opt);
-  } else {
-    r = await readMatrix(new BufReader(new StringReader(input)), opt);
-  }
+): string[][] | Record<string, unknown>[] {
+  const parser = new Parser(opt);
+  const r = parser.parse(input);
+
   if (opt.skipFirstRow || opt.columns) {
     let headers: ColumnOptions[] = [];
     let i = 0;