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nodejs/test/parallel/test-icu-stringwidth.js
Ruben Bridgewater 3646872f60
util: fix width detection for DEL without ICU
This makes sure the DEL character (ASCII 127) is detected as a zero
width character even if Node.js is not built with ICU.

Signed-off-by: Ruben Bridgewater <ruben@bridgewater.de>

PR-URL: https://github.com/nodejs/node/pull/33650
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
2020-06-25 06:42:38 -07:00

96 lines
4.0 KiB
JavaScript

// Flags: --expose-internals
'use strict';
const common = require('../common');
const assert = require('assert');
const { getStringWidth } = require('internal/util/inspect');
// Test column width
// Ll (Lowercase Letter): LATIN SMALL LETTER A
assert.strictEqual(getStringWidth('a'), 1);
assert.strictEqual(getStringWidth(String.fromCharCode(0x0061)), 1);
// Lo (Other Letter)
assert.strictEqual(getStringWidth('丁'), 2);
assert.strictEqual(getStringWidth(String.fromCharCode(0x4E01)), 2);
// Surrogate pairs
assert.strictEqual(getStringWidth('\ud83d\udc78\ud83c\udfff'), 4);
assert.strictEqual(getStringWidth('👅'), 2);
// Cs (Surrogate): High Surrogate
assert.strictEqual(getStringWidth('\ud83d'), 1);
// Cs (Surrogate): Low Surrogate
assert.strictEqual(getStringWidth('\udc78'), 1);
// Cc (Control): NULL
assert.strictEqual(getStringWidth('\u0000'), 0);
// Cc (Control): BELL
assert.strictEqual(getStringWidth(String.fromCharCode(0x0007)), 0);
// Cc (Control): LINE FEED
assert.strictEqual(getStringWidth('\n'), 0);
// Cf (Format): SOFT HYPHEN
assert.strictEqual(getStringWidth(String.fromCharCode(0x00AD)), 1);
// Cf (Format): LEFT-TO-RIGHT MARK
// Cf (Format): RIGHT-TO-LEFT MARK
assert.strictEqual(getStringWidth('\u200Ef\u200F'), 1);
// Cn (Unassigned): Not a character
assert.strictEqual(getStringWidth(String.fromCharCode(0x10FFEF)), 1);
// Cn (Unassigned): Not a character (but in a CJK range)
assert.strictEqual(getStringWidth(String.fromCharCode(0x3FFEF)), 1);
// Mn (Nonspacing Mark): COMBINING ACUTE ACCENT
assert.strictEqual(getStringWidth(String.fromCharCode(0x0301)), 0);
// Mc (Spacing Mark): BALINESE ADEG ADEG
// Chosen as its Canonical_Combining_Class is not 0, but is not a 0-width
// character.
assert.strictEqual(getStringWidth(String.fromCharCode(0x1B44)), 1);
// Me (Enclosing Mark): COMBINING ENCLOSING CIRCLE
assert.strictEqual(getStringWidth(String.fromCharCode(0x20DD)), 0);
// The following is an emoji sequence with ZWJ (zero-width-joiner). In some
// implementations, it is represented as a single glyph, in other
// implementations as a sequence of individual glyphs. By default, each
// component will be counted individually, since not a lot of systems support
// these fully.
// See https://www.unicode.org/reports/tr51/tr51-16.html#Emoji_ZWJ_Sequences
assert.strictEqual(getStringWidth('👩‍👩‍👧‍👧'), 8);
// TODO(BridgeAR): This should have a width of two and six. The heart contains
// the \uFE0F variation selector that indicates that it should be displayed as
// emoji instead of as text. Emojis are all full width characters when not being
// rendered as text.
// https://en.wikipedia.org/wiki/Variation_Selectors_(Unicode_block)
assert.strictEqual(getStringWidth('❤️'), 1);
assert.strictEqual(getStringWidth('👩‍❤️‍👩'), 5);
// The length of one is correct. It is an emoji treated as text.
assert.strictEqual(getStringWidth('❤'), 1);
// By default, unicode characters whose width is considered ambiguous will
// be considered half-width. For these characters, getStringWidth will return
// 1. In some contexts, however, it is more appropriate to consider them full
// width. By default, the algorithm will assume half width.
assert.strictEqual(getStringWidth('\u01d4'), 1);
// Control chars and combining chars are zero
assert.strictEqual(getStringWidth('\u200E\n\u220A\u20D2'), 1);
// Test that the fast path for ASCII characters yields results consistent
// with the 'slow' path.
for (let i = 0; i < 256; i++) {
const char = String.fromCharCode(i);
assert.strictEqual(
getStringWidth(char + '🎉'),
getStringWidth(char) + 2);
if (i < 32 || (i >= 127 && i < 160)) { // Control character
assert.strictEqual(getStringWidth(char), 0);
} else { // Regular ASCII character
assert.strictEqual(getStringWidth(char), 1);
}
}
if (common.hasIntl) {
const a = '한글'.normalize('NFD'); // 한글
const b = '한글'.normalize('NFC'); // 한글
assert.strictEqual(a.length, 6);
assert.strictEqual(b.length, 2);
assert.strictEqual(getStringWidth(a), 4);
assert.strictEqual(getStringWidth(b), 4);
}