japanese yen symbol wrong order before amount bug

Fix Japanese yen symbol in the wrong order before the amount

TL;DR

Do not hand-place the yen sign, let Intl.NumberFormat position it per ja-JP conventions. Japanese puts the yen mark before the amount with no space, and hand-rolled templates get this wrong for some locales. Use the formatter with currency JPY and the locale, and delete the manual symbol placement.

The error

Template renders "$ 1,000" style output for yen: "Y 1000" or "1000 Y"
expected the Japanese convention for yen amounts

Fix it

Step 1: See what the formatter produces for ja-JP

node -e "console.log(new Intl.NumberFormat('ja-JP',{style:'currency',currency:'JPY'}).format(1000))"

Expected: You see the correct conventional rendering.

Step 2: Find the hand-rolled templates

grep -rn "JPY\|yen" src/utils/money.js | head -8

Expected: You see where the symbol is placed manually.

Step 3: Replace manual placement with the formatter

node -e "console.log('delete the template, call the formatter with the order locale and JPY')"

Expected: One code path formats every currency.

Step 4: Spot-check a few currencies and locales

node -e "for(const [l,c] of [['ja-JP','JPY'],['en-US','JPY'],['de-DE','EUR']]) console.log(l, new Intl.NumberFormat(l,{style:'currency',currency:c}).format(1000))"

Expected: Each renders per its locale convention.

When to use this

• Yen amounts show the symbol in the wrong place
• Currency symbols are placed by hand-rolled templates

When NOT to use this

• The symbol is right but the amount is wrong, check the amount
• You need the symbol after the amount deliberately, that is a design choice not a bug

Tool and version compatibility

• Intl.NumberFormat style currency, JPY
• CLDR currency formatting data

Variant phrasings

same issue with euro placement

Identical fix. de-DE puts the euro sign after the amount, hand templates usually put it before.

accounting format needed

Add currencySign: 'accounting'. Placement still comes from the locale.

Why it happens

Currency symbol position is locale data, not a universal rule. Japanese puts the yen sign before the amount, German puts the euro sign after. Templates written for one locale's convention break the others.

Edge cases

• Narrow vs wide yen sign forms exist, the formatter picks per locale
• Do not parse formatted currency back into numbers, keep the raw amount
• JPY has no minor units, the formatter handles that, templates often add .00 wrongly

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_Wa1WX7Y8LNZ5UwL1NEcLYw