diff options
author | Casper Beyer <caspervonb@pm.me> | 2021-02-02 19:05:46 +0800 |
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committer | GitHub <noreply@github.com> | 2021-02-02 12:05:46 +0100 |
commit | 6abf126c2a7a451cded8c6b5e6ddf1b69c84055d (patch) | |
tree | fd94c013a19fcb38954844085821ec1601c20e18 /std/encoding/csv_stringify.ts | |
parent | a2b5d44f1aa9d64f448a2a3cc2001272e2f60b98 (diff) |
chore: remove std directory (#9361)
This removes the std folder from the tree.
Various parts of the tests are pretty tightly dependent
on std (47 direct imports and 75 indirect imports, not
counting the cli tests that use them as fixtures) so I've
added std as a submodule for now.
Diffstat (limited to 'std/encoding/csv_stringify.ts')
-rw-r--r-- | std/encoding/csv_stringify.ts | 172 |
1 files changed, 0 insertions, 172 deletions
diff --git a/std/encoding/csv_stringify.ts b/std/encoding/csv_stringify.ts deleted file mode 100644 index 921631d37..000000000 --- a/std/encoding/csv_stringify.ts +++ /dev/null @@ -1,172 +0,0 @@ -// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license. -// Implements the CSV spec at https://tools.ietf.org/html/rfc4180 - -// This module is browser compatible. - -const QUOTE = '"'; -export const NEWLINE = "\r\n"; - -export class StringifyError extends Error { - readonly name = "StringifyError"; -} - -function getEscapedString(value: unknown, sep: string): string { - if (value === undefined || value === null) return ""; - let str = ""; - - if (typeof value === "object") str = JSON.stringify(value); - else str = String(value); - - // Is regex.test more performant here? If so, how to dynamically create? - // https://stackoverflow.com/questions/3561493/ - if (str.includes(sep) || str.includes(NEWLINE) || str.includes(QUOTE)) { - return `${QUOTE}${str.replaceAll(QUOTE, `${QUOTE}${QUOTE}`)}${QUOTE}`; - } - - return str; -} - -type PropertyAccessor = number | string; - -/** - * @param fn Optional callback for transforming the value - * - * @param header Explicit column header name. If omitted, - * the (final) property accessor is used for this value. - * - * @param prop Property accessor(s) used to access the value on the object - */ -export type ColumnDetails = { - // "unknown" is more type-safe, but inconvenient for user. How to resolve? - // deno-lint-ignore no-explicit-any - fn?: (value: any) => string | Promise<string>; - header?: string; - prop: PropertyAccessor | PropertyAccessor[]; -}; - -export type Column = ColumnDetails | PropertyAccessor | PropertyAccessor[]; - -type NormalizedColumn = Omit<ColumnDetails, "header" | "prop"> & { - header: string; - prop: PropertyAccessor[]; -}; - -function normalizeColumn(column: Column): NormalizedColumn { - let fn: NormalizedColumn["fn"], - header: NormalizedColumn["header"], - prop: NormalizedColumn["prop"]; - - if (typeof column === "object") { - if (Array.isArray(column)) { - header = String(column[column.length - 1]); - prop = column; - } else { - ({ fn } = column); - prop = Array.isArray(column.prop) ? column.prop : [column.prop]; - header = typeof column.header === "string" - ? column.header - : String(prop[prop.length - 1]); - } - } else { - header = String(column); - prop = [column]; - } - - return { fn, header, prop }; -} - -type ObjectWithStringPropertyKeys = Record<string, unknown>; - -/** An object (plain or array) */ -export type DataItem = ObjectWithStringPropertyKeys | unknown[]; - -/** - * Returns an array of values from an object using the property accessors - * (and optional transform function) in each column - */ -async function getValuesFromItem( - item: DataItem, - normalizedColumns: NormalizedColumn[], -): Promise<unknown[]> { - const values: unknown[] = []; - - for (const column of normalizedColumns) { - let value: unknown = item; - - for (const prop of column.prop) { - if (typeof value !== "object" || value === null) continue; - if (Array.isArray(value)) { - if (typeof prop === "number") value = value[prop]; - else { - throw new StringifyError('Property accessor is not of type "number"'); - } - } // I think this assertion is safe. Confirm? - else value = (value as ObjectWithStringPropertyKeys)[prop]; - } - - if (typeof column.fn === "function") value = await column.fn(value); - values.push(value); - } - - return values; -} - -/** - * @param headers Whether or not to include the row of headers. - * Default: `true` - * - * @param separator Delimiter used to separate values. Examples: - * - `","` _comma_ (Default) - * - `"\t"` _tab_ - * - `"|"` _pipe_ - * - etc. - */ -export type StringifyOptions = { - headers?: boolean; - separator?: string; -}; - -/** - * @param data The array of objects to encode - * @param columns Array of values specifying which data to include in the output - * @param options Output formatting options - */ -export async function stringify( - data: DataItem[], - columns: Column[], - options: StringifyOptions = {}, -): Promise<string> { - const { headers, separator: sep } = { - headers: true, - separator: ",", - ...options, - }; - if (sep.includes(QUOTE) || sep.includes(NEWLINE)) { - const message = [ - "Separator cannot include the following strings:", - ' - U+0022: Quotation mark (")', - " - U+000D U+000A: Carriage Return + Line Feed (\\r\\n)", - ].join("\n"); - throw new StringifyError(message); - } - - const normalizedColumns = columns.map(normalizeColumn); - let output = ""; - - if (headers) { - output += normalizedColumns - .map((column) => getEscapedString(column.header, sep)) - .join(sep); - output += NEWLINE; - } - - for (const item of data) { - const values = await getValuesFromItem(item, normalizedColumns); - output += values - .map((value) => getEscapedString(value, sep)) - .join(sep); - output += NEWLINE; - } - - return output; -} |