Merge 821d264 into f78fa2b

i18next · Jan 9, 2024 · 03c563d · 03c563d
2 parents f78fa2b + 821d264
commit 03c563d
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Showing 5 changed files with 59 additions and 7 deletions.
diff --git a/test/typescript/array-access/i18next.d.ts b/test/typescript/array-access/i18next.d.ts
@@ -12,6 +12,11 @@ declare module 'i18next' {
           { fizz: 'buzz' },
           [{ test: 'success'; sub: { deep: 'still success' } }],
         ];
+        arrayJoinWithInterpolation_one: ['{{myName}}, You have', '{{count}}', 'email'];
+        arrayJoinWithInterpolation_other: ['{{myName}}, You have', '{{count}}', 'emails'];
+        key_one: 'item';
+        key_other: 'items';
+        nestedArrayJoin: [['line1', 'line2', 'line3']];
       };
       ctx: {
         dessert: [

diff --git a/test/typescript/array-access/t.test.ts b/test/typescript/array-access/t.test.ts
@@ -46,6 +46,24 @@ describe('main', () => {
     expectTypeOf(t('arrayOfObjects.0', { returnObjects: true })).toEqualTypeOf<{ foo: 'bar' }>();
   });
 
+  it('should work with `count`', () => {
+    expectTypeOf(t('key', { count: 1 })).toEqualTypeOf<'item' | 'items'>();
+  });
+
+  it('should work with `joinArrays`', () => {
+    expectTypeOf(t('arrayOfStrings', { joinArrays: '+' })).toEqualTypeOf<'zero+one'>();
+    expectTypeOf(t('arrayOfObjects', { joinArrays: '+' })).toEqualTypeOf<never>();
+    expectTypeOf(t('nestedArrayJoin.0', { joinArrays: '/' })).toEqualTypeOf<'line1/line2/line3'>();
+    expectTypeOf(
+      t('arrayJoinWithInterpolation', { count: 2, myName: 'Claude', joinArrays: ' ' }),
+    ).toEqualTypeOf<
+      '{{myName}}, You have {{count}} email' | '{{myName}}, You have {{count}} emails'
+    >();
+    expectTypeOf(
+      t('readonlyArrayOfStrings', { joinArrays: ',' }),
+    ).toEqualTypeOf<'readonly zero,readonly one'>();
+  });
+
   it('should work with const keys', () => {
     const alternateTranslationKeys = ['arrayOfStrings.0', 'arrayOfObjects.0.foo'] as const;
 

diff --git a/typescript/helpers.d.ts b/typescript/helpers.d.ts
@@ -3,3 +3,10 @@ export type $Dictionary<T = unknown> = { [key: string]: T };
 export type $OmitArrayKeys<Arr> = Arr extends readonly any[] ? Omit<Arr, keyof any[]> : Arr;
 export type $PreservedValue<Value, Fallback> = [Value] extends [never] ? Fallback : Value;
 export type $SpecialObject = object | Array<string | object>;
+export type $PrependIfDefined<T extends string, S extends string> = T extends '' ? T : `${S}${T}`;
+export type $ConcatArray<T, S extends string, U = never> = T extends readonly [
+  infer F extends string,
+  ...infer R extends string[],
+]
+  ? `${F}${$PrependIfDefined<$ConcatArray<R, S, ''>, S>}`
+  : U;
diff --git a/typescript/options.d.ts b/typescript/options.d.ts
@@ -101,6 +101,11 @@ export type TypeOptions = $MergeBy<
      * Suffix for interpolation
      */
     interpolationSuffix: '}}';
+
+    /**
+     * A string to separate each pair of adjacent elements of the array
+     */
+    joinArrays: false;
   },
   CustomTypeOptions
 >;

diff --git a/typescript/t.d.ts b/typescript/t.d.ts
@@ -1,4 +1,10 @@
-import type { $OmitArrayKeys, $PreservedValue, $Dictionary, $SpecialObject } from './helpers.js';
+import type {
+  $ConcatArray,
+  $OmitArrayKeys,
+  $PreservedValue,
+  $Dictionary,
+  $SpecialObject,
+} from './helpers.js';
 import type {
   TypeOptions,
   Namespace,
@@ -11,6 +17,7 @@ import type {
 /* eslint @typescript-eslint/ban-types: ['error', { types: { "{}": false } }] */
 
 // Type Options
+type _JoinArrays = TypeOptions['joinArrays'];
 type _ReturnObjects = TypeOptions['returnObjects'];
 type _ReturnNull = TypeOptions['returnNull'];
 type _KeySeparator = TypeOptions['keySeparator'];
@@ -83,7 +90,9 @@ type ResourceKeys<WithReturnObjects = _ReturnObjects> = WithReturnObjects extend
 /** **********************************************************************
  * Parse t function keys based on the namespace, options and key prefix *
  *********************************************************************** */
-export type KeysByTOptions<TOpt extends TOptions> = TOpt['returnObjects'] extends true
+export type KeysByTOptions<TOpt extends TOptions> = TOpt['joinArrays'] extends string
+  ? ResourceKeys<true>
+  : TOpt['returnObjects'] extends true
   ? ResourceKeys<true>
   : ResourceKeys;
 
@@ -157,6 +166,10 @@ type ParseTReturnPluralOrdinal<
     string}${_PluralSeparator}ordinal${_PluralSeparator}${PluralSuffix}`,
 > = Res[(KeyWithOrdinalPlural | Key) & keyof Res];
 
+type ParseTReturnJoinArrays<Ret, TOpt extends TOptions = {}> = TOpt['joinArrays'] extends string
+  ? $ConcatArray<Ret, TOpt['joinArrays']>
+  : Ret;
+
 type ParseTReturn<
   Key,
   Res,
@@ -166,17 +179,21 @@ type ParseTReturn<
   : // Process plurals only if count is provided inside options
   TOpt['count'] extends number
   ? TOpt['ordinal'] extends boolean
-    ? ParseTReturnPluralOrdinal<Res, Key>
-    : ParseTReturnPlural<Res, Key>
+    ? ParseTReturnJoinArrays<ParseTReturnPluralOrdinal<Res, Key>, TOpt>
+    : ParseTReturnJoinArrays<ParseTReturnPlural<Res, Key>, TOpt>
   : // otherwise access plain key without adding plural and ordinal suffixes
   Res extends readonly unknown[]
   ? Key extends `${infer NKey extends number}`
-    ? Res[NKey]
+    ? ParseTReturnJoinArrays<Res[NKey], TOpt>
     : never
-  : Res[Key & keyof Res];
+  : ParseTReturnJoinArrays<Res[Key & keyof Res], TOpt>;
 
 type TReturnOptionalNull = _ReturnNull extends true ? null : never;
-type TReturnOptionalObjects<TOpt extends TOptions> = _ReturnObjects extends true
+type TReturnOptionalObjects<TOpt extends TOptions> = _JoinArrays extends string
+  ? string
+  : TOpt['joinArrays'] extends string
+  ? string
+  : _ReturnObjects extends true
   ? $SpecialObject | string
   : TOpt['returnObjects'] extends true
   ? $SpecialObject