🚧 progress: First draft.

Author: make-github-pseudonymous-again

package.json

@@ -65,6 +65,7 @@
     "@babel/preset-env": "7.14.0",
     "@babel/register": "7.13.16",
     "@commitlint/cli": "12.1.1",
+    "@iterable-iterator/map": "^0.1.0",
     "@js-library/commitlint-config": "0.0.4",
     "ava": "3.15.0",
     "babel-plugin-transform-remove-console": "6.9.4",

src/Hit.js

@@ -0,0 +1,7 @@
+export default class Hit {
+	constructor(si, pattern, pi) {
+		this.si = si;
+		this.p = pattern;
+		this.pi = pi;
+	}
+}

src/StringSlice.js

@@ -0,0 +1,7 @@
+export default class StringSlice {
+	constructor(s, i, j) {
+		this.s = s;
+		this.i = i;
+		this.j = j;
+	}
+}

src/data.js

@@ -0,0 +1,39 @@
+const data = [
+	{
+		string: 'abcd',
+		patterns: [
+			{
+				pattern: 'abcde',
+				hits: [],
+			},
+			{
+				pattern: 'abcd',
+				hits: [0],
+			},
+			{
+				pattern: 'bc',
+				hits: [1],
+			},
+		],
+	},
+	{
+		string: 'abcdbdbc',
+		patterns: [
+			{
+				pattern: 'bc',
+				hits: [1, 6],
+			},
+		],
+	},
+	{
+		string: 'abcdbdbcazertyuiopqsdfghjklmwxcvbn',
+		patterns: [
+			{
+				pattern: 'bc',
+				hits: [1, 6],
+			},
+		],
+	},
+];
+
+export default data;

src/index.js

@@ -1,2 +1,5 @@
-const answer = 42;
-export default answer;
+export {default as Hit} from './Hit.js';
+export {default as StringSlice} from './StringSlice.js';
+export {default as data} from './data.js';
+export {default as mock} from './mock.js';
+export {default as single} from './single.js';

src/mock.js

@@ -0,0 +1,26 @@
+import assert from 'assert';
+import StringSlice from './StringSlice.js';
+import Hit from './Hit.js';
+
+/**
+ * A brute-force string searching algorithm leveraging String#indexOf.
+ *
+ * @param {StringSlice} string
+ * @param {Iterable<StringSlice>} patterns
+ * @return {IterableIterator<Hit>}
+ */
+export default function* mock(string, patterns) {
+	assert(string instanceof StringSlice);
+	const s = string.s.slice(string.i, string.j);
+	for (const pattern of patterns) {
+		assert(pattern instanceof StringSlice);
+		const p = pattern.s.slice(pattern.i, pattern.j);
+		let fromIndex = 0;
+		while (true) {
+			const i = s.indexOf(p, fromIndex);
+			if (i === -1) break;
+			yield new Hit(i, pattern, pattern.i);
+			fromIndex = i + 1;
+		}
+	}
+}

src/single.js

@@ -0,0 +1,39 @@
+const single = ({test, algorithms, data}) => {
+	for (const algorithm of algorithms) {
+		for (const {string, patterns} of data) {
+			for (const {pattern, hits} of patterns) {
+				test(macro, algorithm, string, pattern, hits);
+			}
+		}
+	}
+};
+
+export default single;
+
+const macro = (t, algorithm, s, p, hits) => {
+	const name = algorithm.name;
+
+	const si = 0;
+	const sj = s.length;
+	const pi = 0;
+	const pj = p.length;
+
+	let k = 0;
+	for (const i of algorithm(s, si, sj, p, pi, pj)) {
+		if (k < hits.length) {
+			t.is(i, hits[k], `${name} > begin of '${p}' in '${s}'`);
+			++k;
+		} else {
+			++k;
+			t.fail(
+				`"${name} > (${i}) callback called ${k} times for '${p}' in '${s}'`,
+			);
+		}
+	}
+
+	t.is(k, hits.length, `${name} > check number of hits for '${p}' in '${s}'`);
+};
+
+macro.title = (title, algorithm, string, pattern, hits) =>
+	title ??
+	`${algorithm.name}('${string}', '${pattern}') hits ${JSON.stringify(hits)}`;

test/src/api.js

@@ -0,0 +1,17 @@
+import test from 'ava';
+
+import {map} from '@iterable-iterator/map';
+
+import {mock, single, data, StringSlice} from '../../src/index.js';
+
+const mockedSingle = (s, si, sj, p, pi, pj) =>
+	map(
+		(hit) => hit.si,
+		mock(new StringSlice(s, si, sj), [new StringSlice(p, pi, pj)]),
+	);
+
+single({
+	test,
+	algorithms: [mockedSingle],
+	data,
+});