@har-sdk/openapi-sampler/dist/samplers/StringSampler.js

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import RandExp from 'randexp';
export class StringSampler {
    constructor() {
        // ADHOC: 500 seems enough to protect sampler in case of patterns with infinite
        // quantifiers as the complexity may reach O(n^x) for the x quantifier nesting
        this.MAX_PATTERN_SAMPLE_LENGTH = 500;
        this.stringFormats = {
            'email': () => 'jon.snow@targaryen.com',
            'idn-email': () => 'джон.сноу@таргариен.укр',
            'password': (min, max) => this.adjustLength('p@$$w0rd', min, max),
            'date-time': () => '2021-12-31T23:34:00Z',
            'date': () => '2021-12-31',
            'time': () => '23:34:00Z',
            'duration': () => 'P3D',
            'ipv4': () => '208.67.222.222',
            'ipv6': () => '0000:0000:0000:0000:0000:ffff:d043:dcdc',
            'hostname': () => 'brokencrystals.com',
            'idn-hostname': () => 'сломанные-кристаллы.бел',
            'iri': () => 'https://be.wikipedia.org/wiki/%D0%9A%D1%80%D1%8B%D1%88%D1%82%D0%B0%D0%BB%D1%96',
            'iri-reference': () => '/wiki/%D0%9A%D1%80%D1%8B%D1%88%D1%82%D0%B0%D0%BB%D1%96',
            'uri': () => 'https://github.com/NeuraLegion/brokencrystals',
            'uri-reference': () => '../brokencrystals',
            'uri-template': () => 'https://brokencrystals.com/api/file/{provider}',
            'byte': () => 'ZHVtbXkgYmluYXJ5IHNhbXBsZQA=',
            'binary': () => '\x01\x02\x03\x04\x05',
            'base64': () => 'ZHVtbXkgYmluYXJ5IHNhbXBsZQA=',
            'base64url': () => 'bG9yZW0',
            'uuid': () => 'fbdf5a53-161e-4460-98ad-0e39408d8689',
            'json-pointer': () => '/json/pointer',
            'relative-json-pointer': () => '1/relative/json/pointer',
            'regex': () => '/regex/',
            'pattern': (min, max, { pattern }) => this.patternSample(pattern, min, max),
            'default': (min, max) => this.adjustLength('lorem', min, max)
        };
    }
    sample(schema) {
        const encoding = ['base64', 'base64url'].includes(schema.contentEncoding)
            ? schema.contentEncoding
            : schema.contentMediaType === 'application/octet-stream'
                ? 'binary'
                : schema.format;
        const format = schema.pattern ? 'pattern' : encoding || 'default';
        const sampler = this.stringFormats[format] || this.stringFormats['default'];
        const { minLength: min, maxLength: max } = schema;
        return this.checkLength(sampler(min, max, schema), format, min, max);
    }
    patternSample(pattern, min, max) {
        this.assertLength(min, max);
        const randExp = new RandExp(pattern);
        randExp.randInt = (a, b) => Math.floor((a + b) / 2);
        if (min !== undefined) {
            return this.sampleWithMinLength(randExp, min, max);
        }
        randExp.max = max !== null && max !== void 0 ? max : randExp.max;
        const result = randExp.gen();
        return max !== undefined &&
            result.length > max &&
            this.hasInfiniteQuantifier(pattern)
            ? this.sampleWithMaxLength(randExp, max)
            : result;
    }
    hasInfiniteQuantifier(pattern) {
        const pat = typeof pattern === 'string' ? pattern : pattern.source;
        return /(\+|\*|\{\d*,\})/.test(pat);
    }
    sampleWithMaxLength(randExp, max) {
        let result = '';
        for (let i = 1; i <= Math.min(max, 20); i++) {
            randExp.max = Math.floor(max / i);
            result = randExp.gen();
            if (result.length <= max) {
                break;
            }
        }
        return result;
    }
    sampleWithMinLength(randExp, min, max) {
        // ADHOC: make a probe for regex using min quantifier value
        // e.g. ^[a]+[b]+$ expect 'ab', ^[a-z]*$ expect ''
        const randInt = randExp.randInt;
        randExp.max = min;
        randExp.randInt = (a, _) => a;
        let result = randExp.gen();
        randExp.randInt = randInt;
        if (result.length < min) {
            // ADHOC: fallback for failed min quantifier probe with doubled min length
            randExp.max = 2 * min;
            result = this.adjustMaxLength(randExp.gen(), max);
        }
        return result;
    }
    checkLength(value, format, min, max) {
        if ((min && value.length < min) || (max && value.length > max)) {
            const pairs = [
                { key: 'minLength', value: min },
                { key: 'maxLength', value: max },
                { key: 'format', value: format }
            ];
            const boundariesStr = pairs
                .filter((p) => p.value !== undefined)
                .map((p) => `${p.key}=${p.value}`)
                .join(', ');
            throw new Error(`Sample string cannot be generated by boundaries: ${boundariesStr}`);
        }
        return value;
    }
    assertLength(min, max) {
        const pairs = [
            { key: 'minLength', value: min },
            { key: 'maxLength', value: max }
        ];
        const boundariesStr = pairs
            .filter((p) => !this.checkBoundary(p.value))
            .map((p) => `${p.key}=${p.value}`)
            .join(', ');
        if (boundariesStr) {
            throw new Error(`Sample string cannot be generated by boundaries: ${boundariesStr}. Both minLength and maxLength must not exceed ${this.MAX_PATTERN_SAMPLE_LENGTH}`);
        }
    }
    checkBoundary(boundary) {
        return boundary === undefined || boundary <= this.MAX_PATTERN_SAMPLE_LENGTH;
    }
    adjustLength(sample, min, max) {
        const minLength = min ? min : 0;
        const maxLength = max ? max : sample.length;
        return minLength > sample.length
            ? sample
                .repeat(Math.trunc(minLength / sample.length) + 1)
                .substring(0, minLength)
            : sample.substr(0, Math.min(Math.max(sample.length, minLength), maxLength));
    }
    adjustMaxLength(sample, max) {
        return max && sample.length >= max ? sample.substring(0, max) : sample;
    }
}
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