Add German localization for currency symbol placement (with test)

Rules/Languages/de/SharedRules/general.yaml

@@ -317,7 +317,23 @@
           then: [x: "concat('\uF8FE', DefinitionValue($Word, 'Speech', 'PluralForms'))", ct: " "]
           else: [x: "concat('\uF8FE', $Word)", ct: "s"]
 
-
+# Currency symbols precede amounts in MathML but are spoken after them in German: $ 3 -> 3 dollar.
+- name: currency
+  tag: mrow
+  match: "count(*)=3 and DefinitionValue(*[1], 'Speech', 'CurrencySymbols') != ''"
+  variables:
+  - IsSingular: "*[3][self::m:mn and .=1] and *[2]='\u2062'"
+  - CurrencyWord: "DefinitionValue(*[1], 'Speech', 'CurrencySymbols')"
+  replace:
+  - bookmark: "*[3]/@id"
+  - x: "*[3]"
+  - test:
+    - if: "$IsSingular"
+      then: [x: "$CurrencyWord"]
+    - else_if: "DefinitionValue($CurrencyWord, 'Speech', 'PluralForms') != ''"
+      then: [x: "DefinitionValue($CurrencyWord, 'Speech', 'PluralForms')"]
+      else: [x: "$CurrencyWord"]
+
 - name: sin
   tag: mi
   match: ".='sin'"

tests/Languages/de/units.rs

@@ -103,6 +103,23 @@ fn non_si_unit_plural_regression() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn currency_symbol_precedes_amount() -> Result<()> {
+    // German speaks a prefixed currency symbol after its amount.
+    let expr = r#"<math><mi>$</mi><mn>3</mn></math>"#;
+    test("de", "ClearSpeak", expr, "3 dollar")?;
+    test("de", "SimpleSpeak", expr, "3 dollar")?;
+
+    let expr = r#"<math><mi>€</mi><mn>1</mn></math>"#;
+    test("de", "ClearSpeak", expr, "1 euro")?;
+    test("de", "SimpleSpeak", expr, "1 euro")?;
+
+    let expr = r#"<math><mi>£</mi><mn>4,7</mn></math>"#;
+    test("de", "ClearSpeak", expr, "4,7 pfund")?;
+    test("de", "SimpleSpeak", expr, "4,7 pfund")?;
+    Ok(())
+}
+
 /*
 #[test]
 fn si_base_with_prefixes() -> Result<()> {