diff options
Diffstat (limited to 'op_crates/web/01_mimesniff.js')
| -rw-r--r-- | op_crates/web/01_mimesniff.js | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/op_crates/web/01_mimesniff.js b/op_crates/web/01_mimesniff.js new file mode 100644 index 000000000..918343f2c --- /dev/null +++ b/op_crates/web/01_mimesniff.js @@ -0,0 +1,242 @@ +// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license. + +// @ts-check +/// <reference path="../../core/lib.deno_core.d.ts" /> +/// <reference path="../web/internal.d.ts" /> +/// <reference path="../web/lib.deno_web.d.ts" /> + +"use strict"; + +((window) => { + const { collectSequenceOfCodepoints } = window.__bootstrap.infra; + + const HTTP_TAB_OR_SPACE = ["\u0009", "\u0020"]; + const HTTP_WHITESPACE = ["\u000A", "\u000D", ...HTTP_TAB_OR_SPACE]; + + const ASCII_DIGIT = ["\u0030-\u0039"]; + const ASCII_UPPER_ALPHA = ["\u0041-\u005A"]; + const ASCII_LOWER_ALPHA = ["\u0061-\u007A"]; + const ASCII_ALPHA = [...ASCII_UPPER_ALPHA, ...ASCII_LOWER_ALPHA]; + const ASCII_ALPHANUMERIC = [...ASCII_DIGIT, ...ASCII_ALPHA]; + const HTTP_TOKEN_CODE_POINT = [ + "\u0021", + "\u0023", + "\u0025", + "\u0026", + "\u0027", + "\u002A", + "\u002B", + "\u002D", + "\u002E", + "\u005E", + "\u005F", + "\u0060", + "\u007C", + "\u007E", + ...ASCII_ALPHANUMERIC, + ]; + const HTTP_TOKEN_CODE_POINT_RE = new RegExp(`^[${HTTP_TOKEN_CODE_POINT}]+$`); + const HTTP_QUOTED_STRING_TOKEN_POINT = [ + "\u0009", + "\u0020-\u007E", + "\u0080-\u00FF", + ]; + const HTTP_QUOTED_STRING_TOKEN_POINT_RE = new RegExp( + `^[${HTTP_QUOTED_STRING_TOKEN_POINT}]+$`, + ); + + /** + * https://fetch.spec.whatwg.org/#collect-an-http-quoted-string + * @param {string} input + * @param {number} position + * @param {boolean} extractValue + * @returns {{result: string, position: number}} + */ + function collectHttpQuotedString(input, position, extractValue) { + // 1. + const positionStart = position; + // 2. + let value = ""; + // 3. + if (input[position] !== "\u0022") throw new Error('must be "'); + // 4. + position++; + // 5. + while (true) { + // 5.1. + const res = collectSequenceOfCodepoints( + input, + position, + (c) => c !== "\u0022" && c !== "\u005C", + ); + value += res.result; + position = res.position; + // 5.2. + if (position >= input.length) break; + // 5.3. + const quoteOrBackslash = input[position]; + // 5.4. + position++; + // 5.5. + if (quoteOrBackslash === "\u005C") { + // 5.5.1. + if (position >= input.length) { + value += "\u005C"; + break; + } + // 5.5.2. + value += input[position]; + // 5.5.3. + position++; + } else { // 5.6. + // 5.6.1 + if (input[position] !== "\u0022") throw new Error('must be "'); + // 5.6.2 + break; + } + } + // 6. + if (extractValue) return { result: value, position }; + // 7. + return { result: input.substring(positionStart, position + 1), position }; + } + + /** + * @param {string} input + */ + function parseMimeType(input) { + // 1. + input = input.replaceAll(new RegExp(`^[${HTTP_WHITESPACE}]+`, "g"), ""); + input = input.replaceAll(new RegExp(`[${HTTP_WHITESPACE}]+$`, "g"), ""); + + // 2. + let position = 0; + const endOfInput = input.length; + + // 3. + const res1 = collectSequenceOfCodepoints( + input, + position, + (c) => c != "\u002F", + ); + const type = res1.result; + position = res1.position; + + // 4. + if (type === "" || !HTTP_TOKEN_CODE_POINT_RE.test(type)) { + return null; + } + + // 5. + if (position >= endOfInput) return null; + + // 6. + position++; + + // 7. + const res2 = collectSequenceOfCodepoints( + input, + position, + (c) => c != "\u003B", + ); + let subtype = res2.result; + position = res2.position; + + // 8. + subtype = subtype.replaceAll(new RegExp(`[${HTTP_WHITESPACE}]+$`, "g"), ""); + + // 9. + if (subtype === "" || !HTTP_TOKEN_CODE_POINT_RE.test(subtype)) { + return null; + } + + // 10. + const mimeType = { + type: type.toLowerCase(), + subtype: subtype.toLowerCase(), + /** @type {Map<string, string>} */ + parameters: new Map(), + }; + + // 11. + while (position < endOfInput) { + // 11.1. + position++; + + // 11.2. + const res1 = collectSequenceOfCodepoints( + input, + position, + (c) => HTTP_WHITESPACE.includes(c), + ); + position = res1.position; + + // 11.3. + const res2 = collectSequenceOfCodepoints( + input, + position, + (c) => c !== "\u003B" && c !== "\u003D", + ); + let parameterName = res2.result; + position = res2.position; + + // 11.4. + parameterName = parameterName.toLowerCase(); + + // 11.5. + if (position < endOfInput) { + if (input[position] == "\u003B") continue; + position++; + } + + // 11.6. + if (position >= endOfInput) break; + + // 11.7. + let parameterValue = null; + + // 11.8. + if (input[position] == "\u0022") { + // 11.8.1. + const res = collectHttpQuotedString(input, position, true); + parameterValue = res.result; + position = res.position; + + // 11.8.2. + position++; + } else { // 11.9. + // 11.9.1. + const res = collectSequenceOfCodepoints( + input, + position, + (c) => c !== "\u003B", + ); + parameterValue = res.result; + position = res.position; + + // 11.9.2. + parameterValue = parameterValue.replaceAll( + new RegExp(`[${HTTP_WHITESPACE}]+$`, "g"), + "", + ); + + // 11.9.3. + if (parameterValue === "") continue; + } + + // 11.9. + if ( + parameterName !== "" && HTTP_TOKEN_CODE_POINT_RE.test(parameterName) && + HTTP_QUOTED_STRING_TOKEN_POINT_RE.test(parameterValue) && + !mimeType.parameters.has(parameterName) + ) { + mimeType.parameters.set(parameterName, parameterValue); + } + } + + // 12. + return mimeType; + } + + window.__bootstrap.mimesniff = { parseMimeType }; +})(this); |