Add support for 'leading' digits in render_currency

docs/docs/report/helpers.md

@@ -556,9 +556,28 @@ The locale is resolved in the following priority order:
 1. **Explicit `locale=` argument** — highest priority, always wins
 2. **Server `LANGUAGE_CODE`** — fallback
 
+#### Leading Digits
+
+The `leading` argument specifies the minimum number of digits to render before the decimal point (zero-padded). This works identically to `leading` in [`format_number`](#format_number):
+
+```html
+{% raw %}
+{% load report %}
+
+<!-- default: no padding -->
+{% render_currency order.total_price currency='USD' %}
+<!-- output: $1.23 -->
+
+<!-- force at least 4 integer digits -->
+{% render_currency order.total_price currency='USD' leading=4 %}
+<!-- output: $0,001.23 -->
+
+{% endraw %}
+```
+
 #### Custom Format Strings
 
-The `fmt` argument accepts a [Unicode number pattern](https://unicode.org/reports/tr35/tr35-numbers.html#Number_Format_Patterns) string (same syntax as [`format_number`](#custom-format-strings)). **When `fmt` is provided, it takes complete priority over `decimal_places` and `max_decimal_places`** — those arguments are ignored.
+The `fmt` argument accepts a [Unicode number pattern](https://unicode.org/reports/tr35/tr35-numbers.html#Number_Format_Patterns) string (same syntax as [`format_number`](#custom-format-strings)). **When `fmt` is provided, it takes complete priority over `decimal_places`, `max_decimal_places`, and `leading`** — those arguments are ignored.
 
 The `locale`, `currency`, `multiplier`, and `include_symbol` arguments are still applied when `fmt` is set.
 

src/backend/InvenTree/report/templatetags/report.py

@@ -797,12 +797,13 @@ def modulo(x: Any, y: Any, cast: Optional[type] = None) -> Any:
 
 @register.simple_tag
 def render_currency(
-    money,
+    money: Money | str | int | float | Decimal,
     decimal_places: Optional[int] = None,
     currency: Optional[str] = None,
     multiplier: Optional[Decimal] = None,
     max_decimal_places: Optional[int] = None,
     include_symbol: bool = True,
+    leading: Optional[int] = None,
     fmt: Optional[str] = None,
     locale: Optional[str] = None,
     **kwargs,
@@ -816,12 +817,14 @@ def render_currency(
         decimal_places: Minimum (forced) decimal places, e.g. decimal_places=2 gives '.00'. Defaults to the locale/currency standard.
         max_decimal_places: Maximum decimal places (optional digits beyond decimal_places), e.g. max_decimal_places=4 allows up to 4.
         include_symbol: If True, include the currency symbol in the output
-        fmt: Optional Babel number pattern string. When provided, takes priority over all decimal_places options.
+        leading: Minimum number of leading digits to render before the decimal point (default = 1)
+        fmt: Optional Babel number pattern string. When provided, takes priority over all other formatting options.
         locale: Optional locale override (e.g. 'en-us', 'de-de'). Defaults to server LANGUAGE_CODE.
     """
     if money in [None, '']:
         return '-'
 
+    # If the supplied value is *not* a Money instance, attempt to convert it into one
     if not isinstance(money, Money):
         try:
             money = Money(
@@ -829,9 +832,7 @@ def render_currency(
                 currency or get_global_setting('INVENTREE_DEFAULT_CURRENCY'),
             )
         except Exception:
-            raise ValidationError(
-                'render_currency: invalid money value: ' + repr(money)
-            )
+            raise ValidationError(f'render_currency: invalid money value - {money!r}')
 
     if currency is not None:
         try:
@@ -844,7 +845,7 @@ def render_currency(
             money *= Decimal(str(multiplier).strip())
         except Exception:
             raise ValidationError(
-                'render_currency: invalid multiplier value: ' + repr(multiplier)
+                f'render_currency: invalid multiplier value - {multiplier!r}'
             )
 
     locale = get_locale(locale)
@@ -870,6 +871,15 @@ def render_currency(
 
     pattern.frac_prec = (decimal_places, max(decimal_places, max_decimal_places))
 
+    if leading is not None:
+        try:
+            leading = int(leading) or 0
+        except (ValueError, TypeError):
+            leading = 0
+        if leading > 0:
+            min_int, max_int = pattern.int_prec
+            pattern.int_prec = (max(leading, min_int), max(leading, max_int))
+
     return pattern.apply(
         money.amount,
         locale,

src/backend/InvenTree/report/test_tags.py

@@ -609,6 +609,24 @@ class ReportTagTest(PartImageTestMixin, InvenTreeTestCase):
             report_tags.render_currency(m, fmt='0.0000', decimal_places=2), '1234.5600'
         )
 
+        # Test leading digits
+        m_small = Money(1.23, 'USD')
+        self.assertEqual(
+            report_tags.render_currency(m_small, leading=4, locale='en-us'), '$0,001.23'
+        )
+        # leading=1 is the default — no change
+        self.assertEqual(
+            report_tags.render_currency(m_small, leading=1, locale='en-us'), '$1.23'
+        )
+        # invalid leading falls back gracefully
+        self.assertEqual(
+            report_tags.render_currency(m_small, leading='x', locale='en-us'), '$1.23'
+        )
+        # fmt takes priority over leading
+        self.assertEqual(
+            report_tags.render_currency(m_small, leading=6, fmt='#,##0.00'), '1.23'
+        )
+
     def test_render_currency_locale_override(self):
         """Explicit locale= kwarg takes priority over global setting and system locale."""
         m = Money(1234.56, 'USD')