fix: correctly interpret digits followed by multiple powers of ten

Fixes #1399.

CHANGELOG.md

@@ -8,14 +8,16 @@ app.
 
 ## [Unreleased]
 
-- Changed puck behavior to no longer hold the popup window like a regular
-  mouse event would ([#1767](https://github.com/birchill/10ten-ja-reader/discussions/1767)).
 - Made it possible to change tabs in the popup by swiping horizontally
   thanks to [@StarScape](https://github.com/StarScape)
   ([#1656](https://github.com/birchill/10ten-ja-reader/issues/1656)).
 - Bundled fonts used by the popup to provide consistent display and avoid issues
   with sites that patch system fonts
   ([#1560](https://github.com/birchill/10ten-ja-reader/issues/1560)).
+- Changed puck behavior to no longer hold the popup window like a regular
+  mouse event would
+  thanks to [@StarScape](https://github.com/StarScape)
+  ([#1767](https://github.com/birchill/10ten-ja-reader/discussions/1767)).
 - Made copying to the clipboard include rare headwords again when not using
   simplified copy mode
   ([#1665](https://github.com/birchill/10ten-ja-reader/issues/1665)).
@@ -34,6 +36,9 @@ app.
   ([#1677](https://github.com/birchill/10ten-ja-reader/issues/1677)).
 - Made senses no longer be restricted when matching on search-only headwords
   ([#1551](https://github.com/birchill/10ten-ja-reader/issues/1551)).
+- Fixed translation of odd numbers with digits and multiple powers of ten like
+  11,786百万円
+  ([#1399](https://github.com/birchill/10ten-ja-reader/issues/1399)).
 
 ## [1.18.0] - 2024-02-26
 

src/content/numbers.test.ts

@@ -48,6 +48,9 @@ describe('parseNumber', () => {
     expect(parseNumber('1.2億')).toEqual(120000000);
     // As seen here: https://www.athome.co.jp/kodate/1008941087/
     expect(parseNumber('39,800万')).toEqual(398_000_000);
+    // https://github.com/birchill/10ten-ja-reader/issues/1399
+    expect(parseNumber('11,786百万')).toEqual(11_786_000_000);
+    expect(parseNumber('123,456,789百万')).toEqual(123_456_789_000_000);
 
     // Bogus inputs
 

src/content/numbers.ts

@@ -111,16 +111,14 @@ export function parseNumber(inputText: string): number | null {
   let numbers = digits as Array<number>;
 
   // Special case where we have a series of digits followed by a power of ten,
-  // e.g. 39,800万円. These don't follow the usual rules of numbers so we treat
-  // them separately.
-  if (
-    numbers.length > 1 &&
-    numbers.slice(0, -1).every((d) => d >= 0 && d < 10) &&
-    numbers[numbers.length - 1]! >= 100
-  ) {
-    const powerOfTen = numbers.pop()!;
-    const multiplier = numbers.reduce((acc, d) => acc * 10 + d, 0);
-    return multiplier * powerOfTen;
+  // e.g. 39,800万円 and 11,786百万. These don't follow the usual rules of
+  // numbers so we treat them separately.
+  const digitsAndPowersOfTen = getDigitsAndPowersOfTen(numbers);
+  if (digitsAndPowersOfTen) {
+    const [digits, powersOfTen] = digitsAndPowersOfTen;
+    const multiplier = digits.reduce((acc, d) => acc * 10 + d, 0);
+    const base = powersOfTen.reduce((acc, p) => acc * p, 1);
+    return multiplier * base;
   }
 
   let result = 0;
@@ -173,6 +171,26 @@ export function parseNumber(inputText: string): number | null {
   return result + (numbers.length ? numbers[0] : 0);
 }
 
+function getDigitsAndPowersOfTen(
+  arr: Array<number>
+): [Array<number>, Array<number>] | null {
+  let lastPowerOfTen = arr.length;
+  while (lastPowerOfTen && arr[lastPowerOfTen - 1] >= 100) {
+    --lastPowerOfTen;
+  }
+
+  if (lastPowerOfTen === 0 || lastPowerOfTen === arr.length) {
+    return null;
+  }
+
+  const digits = arr.slice(0, lastPowerOfTen);
+  if (!digits.every((d) => d >= 0 && d < 10)) {
+    return null;
+  }
+
+  return [digits, arr.slice(lastPowerOfTen)];
+}
+
 function validSequence(c1: number, c2: number): boolean {
   // If we have xxx万, xxx億, xxx兆 then the only requirement is that xxx is less
   // than the 'base'.