Updated text expansion feature

bin/pseudo-localize

@@ -66,15 +66,13 @@ const convert = function(input) {
   const options = { strategy: argv.strategy };
 
   if (typeof input === 'string') {
-    write(localize(input, options));
+    write(localize(input, options) +'\n');
     return;
   }
-
   // Flatten nested translation JSONs
   input = flatten(input, {
     safe: true,
   });
-
   for (let key in input) {
     // this will need to be updated if other primitives
     // support pseudo-localization
@@ -97,7 +95,7 @@ const convert = function(input) {
   let json = null;
 
   if (argv.i) {
-    convert(argv.i + '\n');
+    convert(argv.i);
     return;
   }
 

src/localize.js

@@ -125,20 +125,68 @@ const strategies = {
   },
 };
 
+// Reference for ratios https://www.w3.org/International/articles/article-text-size
+const numOfCharactersInEnglishToExpansionRatioMap = {
+  10: 2.5,
+  20: 1.9,
+  30: 1.7,
+  40: 1.5,
+  50: 1.5,
+  60: 1.6,
+  70: 1.6,
+  over70: 1.3,
+};
+
+const isAlpha = character => {
+  return /[a-zA-Z]/.test(character);
+};
+
+const textExpander = (string, numDuplicateChars = 0, expansionRatio = 1) => {
+  const repeatTimes = Math.ceil(expansionRatio);
+  const reverseString = string.split('').reverse();
+
+  let expandedText = '';
+  let count = 0;
+  let maxIndex = numDuplicateChars + string.length;
+
+  for (const c of reverseString) {
+    if (isAlpha(c) && count < numDuplicateChars) {
+      expandedText += c.repeat(repeatTimes);
+      count += repeatTimes - 1;
+    } else {
+      expandedText += c;
+    }
+  }
+
+  return expandedText
+    .split('')
+    .reverse()
+    .join('')
+    .substring(0, maxIndex);
+};
+
+const textExpansionHandler = (string, toBeExpanded) => {
+  const strLen = string.length;
+  const ratioKey = Math.ceil(strLen / 10) * 10;
+  const ratio =
+    ratioKey > 70
+      ? numOfCharactersInEnglishToExpansionRatioMap.over70
+      : numOfCharactersInEnglishToExpansionRatioMap[ratioKey];
+  const numDuplicateChars = Math.ceil(strLen * ratio) - strLen;
+
+  if (toBeExpanded) return textExpander(string, numDuplicateChars, ratio);
+  else return textExpander(string);
+};
+
 const pseudoLocalizeString = (string, { strategy = 'accented' } = {}) => {
   let opts = strategies[strategy];
+  let expandedString = textExpansionHandler(string, opts.elongate);
 
   let pseudoLocalizedText = '';
-  for (let character of string) {
+
+  for (let character of expandedString) {
     if (opts.map[character]) {
-      const cl = character.toLowerCase();
-      // duplicate "a", "e", "o" and "u" to emulate ~30% longer text
-      if (
-        opts.elongate &&
-        (cl === 'a' || cl === 'e' || cl === 'o' || cl === 'u')
-      ) {
-        pseudoLocalizedText += opts.map[character] + opts.map[character];
-      } else pseudoLocalizedText += opts.map[character];
+      pseudoLocalizedText += opts.map[character];
     } else pseudoLocalizedText += character;
   }
 
@@ -149,6 +197,7 @@ const pseudoLocalizeString = (string, { strategy = 'accented' } = {}) => {
   ) {
     return pseudoLocalizedText;
   }
+
   return opts.prefix + pseudoLocalizedText + opts.postfix;
 };
 

src/localize.test.js

@@ -2,13 +2,13 @@ import localize from './localize';
 
 describe('localize', () => {
   test('accented', () => {
-    expect(localize('abcd')).toBe('ȧȧƀƈḓ');
+    expect(localize('abcd')).toBe('ȧƀƀƀƈƈƈḓḓḓ');
     // aeou are duplicated
-    expect(localize('aeou')).toBe('ȧȧḗḗǿǿŭŭ');
-    expect(localize('foo bar')).toBe('ƒǿǿǿǿ ƀȧȧř');
-    expect(localize('CAPITAL_LETTERS')).toBe('ƇȦȦƤĪŦȦȦĿ_ĿḖḖŦŦḖḖŘŞ');
+    expect(localize('aeou')).toBe('ȧḗḗḗǿǿǿŭŭŭ');
+    expect(localize('foo bar')).toBe('ƒƒƒǿǿǿǿǿǿ ƀƀƀȧȧȧřř');
+    expect(localize('CAPITAL_LETTERS')).toBe('ƇƇȦȦƤƤĪĪŦŦȦȦĿĿ_ĿĿḖḖŦŦŦŦḖḖŘŘŞŞ');
     // Everything except ASCII alphabet is passed through
-    expect(localize('123,. n -~ðÞ')).toBe('123,. ƞ -~ðÞ');
+    expect(localize('123,. n -~ðÞ')).toBe('123,. ƞƞ -~ðÞ');
   });
 
   test('bidi', () => {