Files
didier amyot 1f2ea8b7e5 Added test package in nix flake to automatically run tests.
To be able to do such, it was required to add the vendor directory
to the git project.
2023-06-10 09:33:04 -04:00

441 lines
11 KiB
TypeScript

// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
// This module is browser compatible.
import {
bgGreen,
bgRed,
bold,
gray,
green,
red,
white,
} from "../fmt/colors.ts";
interface FarthestPoint {
y: number;
id: number;
}
export enum DiffType {
removed = "removed",
common = "common",
added = "added",
}
export interface DiffResult<T> {
type: DiffType;
value: T;
details?: Array<DiffResult<T>>;
}
const REMOVED = 1;
const COMMON = 2;
const ADDED = 3;
function createCommon<T>(A: T[], B: T[], reverse?: boolean): T[] {
const common = [];
if (A.length === 0 || B.length === 0) return [];
for (let i = 0; i < Math.min(A.length, B.length); i += 1) {
if (
A[reverse ? A.length - i - 1 : i] === B[reverse ? B.length - i - 1 : i]
) {
common.push(A[reverse ? A.length - i - 1 : i]);
} else {
return common;
}
}
return common;
}
/**
* Renders the differences between the actual and expected values
* @param A Actual value
* @param B Expected value
*/
export function diff<T>(A: T[], B: T[]): Array<DiffResult<T>> {
const prefixCommon = createCommon(A, B);
const suffixCommon = createCommon(
A.slice(prefixCommon.length),
B.slice(prefixCommon.length),
true,
).reverse();
A = suffixCommon.length
? A.slice(prefixCommon.length, -suffixCommon.length)
: A.slice(prefixCommon.length);
B = suffixCommon.length
? B.slice(prefixCommon.length, -suffixCommon.length)
: B.slice(prefixCommon.length);
const swapped = B.length > A.length;
[A, B] = swapped ? [B, A] : [A, B];
const M = A.length;
const N = B.length;
if (!M && !N && !suffixCommon.length && !prefixCommon.length) return [];
if (!N) {
return [
...prefixCommon.map(
(c): DiffResult<typeof c> => ({ type: DiffType.common, value: c }),
),
...A.map(
(a): DiffResult<typeof a> => ({
type: swapped ? DiffType.added : DiffType.removed,
value: a,
}),
),
...suffixCommon.map(
(c): DiffResult<typeof c> => ({ type: DiffType.common, value: c }),
),
];
}
const offset = N;
const delta = M - N;
const size = M + N + 1;
const fp: FarthestPoint[] = Array.from(
{ length: size },
() => ({ y: -1, id: -1 }),
);
/**
* INFO:
* This buffer is used to save memory and improve performance.
* The first half is used to save route and last half is used to save diff
* type.
* This is because, when I kept new uint8array area to save type,performance
* worsened.
*/
const routes = new Uint32Array((M * N + size + 1) * 2);
const diffTypesPtrOffset = routes.length / 2;
let ptr = 0;
let p = -1;
function backTrace<T>(
A: T[],
B: T[],
current: FarthestPoint,
swapped: boolean,
): Array<{
type: DiffType;
value: T;
}> {
const M = A.length;
const N = B.length;
const result = [];
let a = M - 1;
let b = N - 1;
let j = routes[current.id];
let type = routes[current.id + diffTypesPtrOffset];
while (true) {
if (!j && !type) break;
const prev = j;
if (type === REMOVED) {
result.unshift({
type: swapped ? DiffType.removed : DiffType.added,
value: B[b],
});
b -= 1;
} else if (type === ADDED) {
result.unshift({
type: swapped ? DiffType.added : DiffType.removed,
value: A[a],
});
a -= 1;
} else {
result.unshift({ type: DiffType.common, value: A[a] });
a -= 1;
b -= 1;
}
j = routes[prev];
type = routes[prev + diffTypesPtrOffset];
}
return result;
}
function createFP(
slide: FarthestPoint,
down: FarthestPoint,
k: number,
M: number,
): FarthestPoint {
if (slide && slide.y === -1 && down && down.y === -1) {
return { y: 0, id: 0 };
}
if (
(down && down.y === -1) ||
k === M ||
(slide && slide.y) > (down && down.y) + 1
) {
const prev = slide.id;
ptr++;
routes[ptr] = prev;
routes[ptr + diffTypesPtrOffset] = ADDED;
return { y: slide.y, id: ptr };
} else {
const prev = down.id;
ptr++;
routes[ptr] = prev;
routes[ptr + diffTypesPtrOffset] = REMOVED;
return { y: down.y + 1, id: ptr };
}
}
function snake<T>(
k: number,
slide: FarthestPoint,
down: FarthestPoint,
_offset: number,
A: T[],
B: T[],
): FarthestPoint {
const M = A.length;
const N = B.length;
if (k < -N || M < k) return { y: -1, id: -1 };
const fp = createFP(slide, down, k, M);
while (fp.y + k < M && fp.y < N && A[fp.y + k] === B[fp.y]) {
const prev = fp.id;
ptr++;
fp.id = ptr;
fp.y += 1;
routes[ptr] = prev;
routes[ptr + diffTypesPtrOffset] = COMMON;
}
return fp;
}
while (fp[delta + offset].y < N) {
p = p + 1;
for (let k = -p; k < delta; ++k) {
fp[k + offset] = snake(
k,
fp[k - 1 + offset],
fp[k + 1 + offset],
offset,
A,
B,
);
}
for (let k = delta + p; k > delta; --k) {
fp[k + offset] = snake(
k,
fp[k - 1 + offset],
fp[k + 1 + offset],
offset,
A,
B,
);
}
fp[delta + offset] = snake(
delta,
fp[delta - 1 + offset],
fp[delta + 1 + offset],
offset,
A,
B,
);
}
return [
...prefixCommon.map(
(c): DiffResult<typeof c> => ({ type: DiffType.common, value: c }),
),
...backTrace(A, B, fp[delta + offset], swapped),
...suffixCommon.map(
(c): DiffResult<typeof c> => ({ type: DiffType.common, value: c }),
),
];
}
/**
* Renders the differences between the actual and expected strings
* Partially inspired from https://github.com/kpdecker/jsdiff
* @param A Actual string
* @param B Expected string
*/
export function diffstr(A: string, B: string) {
function unescape(string: string): string {
// unescape invisible characters.
// ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String#escape_sequences
return string
.replaceAll("\b", "\\b")
.replaceAll("\f", "\\f")
.replaceAll("\t", "\\t")
.replaceAll("\v", "\\v")
.replaceAll( // does not remove line breaks
/\r\n|\r|\n/g,
(str) => str === "\r" ? "\\r" : str === "\n" ? "\\n\n" : "\\r\\n\r\n",
);
}
function tokenize(string: string, { wordDiff = false } = {}): string[] {
if (wordDiff) {
// Split string on whitespace symbols
const tokens = string.split(/([^\S\r\n]+|[()[\]{}'"\r\n]|\b)/);
// Extended Latin character set
const words =
/^[a-zA-Z\u{C0}-\u{FF}\u{D8}-\u{F6}\u{F8}-\u{2C6}\u{2C8}-\u{2D7}\u{2DE}-\u{2FF}\u{1E00}-\u{1EFF}]+$/u;
// Join boundary splits that we do not consider to be boundaries and merge empty strings surrounded by word chars
for (let i = 0; i < tokens.length - 1; i++) {
if (
!tokens[i + 1] && tokens[i + 2] && words.test(tokens[i]) &&
words.test(tokens[i + 2])
) {
tokens[i] += tokens[i + 2];
tokens.splice(i + 1, 2);
i--;
}
}
return tokens.filter((token) => token);
} else {
// Split string on new lines symbols
const tokens = [], lines = string.split(/(\n|\r\n)/);
// Ignore final empty token when text ends with a newline
if (!lines[lines.length - 1]) {
lines.pop();
}
// Merge the content and line separators into single tokens
for (let i = 0; i < lines.length; i++) {
if (i % 2) {
tokens[tokens.length - 1] += lines[i];
} else {
tokens.push(lines[i]);
}
}
return tokens;
}
}
// Create details by filtering relevant word-diff for current line
// and merge "space-diff" if surrounded by word-diff for cleaner displays
function createDetails(
line: DiffResult<string>,
tokens: Array<DiffResult<string>>,
) {
return tokens.filter(({ type }) =>
type === line.type || type === DiffType.common
).map((result, i, t) => {
if (
(result.type === DiffType.common) && (t[i - 1]) &&
(t[i - 1]?.type === t[i + 1]?.type) && /\s+/.test(result.value)
) {
return {
...result,
type: t[i - 1].type,
};
}
return result;
});
}
// Compute multi-line diff
const diffResult = diff(
tokenize(`${unescape(A)}\n`),
tokenize(`${unescape(B)}\n`),
);
const added = [], removed = [];
for (const result of diffResult) {
if (result.type === DiffType.added) {
added.push(result);
}
if (result.type === DiffType.removed) {
removed.push(result);
}
}
// Compute word-diff
const aLines = added.length < removed.length ? added : removed;
const bLines = aLines === removed ? added : removed;
for (const a of aLines) {
let tokens = [] as Array<DiffResult<string>>,
b: undefined | DiffResult<string>;
// Search another diff line with at least one common token
while (bLines.length) {
b = bLines.shift();
tokens = diff(
tokenize(a.value, { wordDiff: true }),
tokenize(b?.value ?? "", { wordDiff: true }),
);
if (
tokens.some(({ type, value }) =>
type === DiffType.common && value.trim().length
)
) {
break;
}
}
// Register word-diff details
a.details = createDetails(a, tokens);
if (b) {
b.details = createDetails(b, tokens);
}
}
return diffResult;
}
/**
* Colors the output of assertion diffs
* @param diffType Difference type, either added or removed
*/
function createColor(
diffType: DiffType,
{ background = false } = {},
): (s: string) => string {
// TODO(@littledivy): Remove this when we can detect
// true color terminals.
// https://github.com/denoland/deno_std/issues/2575
background = false;
switch (diffType) {
case DiffType.added:
return (s: string): string =>
background ? bgGreen(white(s)) : green(bold(s));
case DiffType.removed:
return (s: string): string => background ? bgRed(white(s)) : red(bold(s));
default:
return white;
}
}
/**
* Prefixes `+` or `-` in diff output
* @param diffType Difference type, either added or removed
*/
function createSign(diffType: DiffType): string {
switch (diffType) {
case DiffType.added:
return "+ ";
case DiffType.removed:
return "- ";
default:
return " ";
}
}
export function buildMessage(
diffResult: ReadonlyArray<DiffResult<string>>,
{ stringDiff = false } = {},
): string[] {
const messages: string[] = [], diffMessages: string[] = [];
messages.push("");
messages.push("");
messages.push(
` ${gray(bold("[Diff]"))} ${red(bold("Actual"))} / ${
green(bold("Expected"))
}`,
);
messages.push("");
messages.push("");
diffResult.forEach((result: DiffResult<string>) => {
const c = createColor(result.type);
const line = result.details?.map((detail) =>
detail.type !== DiffType.common
? createColor(detail.type, { background: true })(detail.value)
: detail.value
).join("") ?? result.value;
diffMessages.push(c(`${createSign(result.type)}${line}`));
});
messages.push(...(stringDiff ? [diffMessages.join("")] : diffMessages));
messages.push("");
return messages;
}