fix(math): respect locale for full slash dates (#738)

Author: antonreshetov

src/renderer/composables/__tests__/useMathEngine.math.test.ts

@@ -19,6 +19,10 @@ describe('arithmetic', () => {
   it('subtraction', () => expectValue('20 - 3', '17'))
   it('multiplication', () => expectValue('4 * 5', '20'))
   it('division', () => expectValue('100 / 4', '25'))
+  it('prefers division over ambiguous slash dates', () => {
+    expectNumericClose('4/3', 4 / 3, 4)
+    expectNumericClose('22/11', 2, 4)
+  })
   it('parentheses', () => expectValue('(2 + 3) * 4', '20'))
   it('exponent', () => expectValue('2 ^ 10', '1,024'))
   it('negative numbers', () => expectValue('-5 + 3', '-2'))
@@ -33,6 +37,32 @@ describe('arithmetic', () => {
   })
 })
 
+describe('locale-aware full slash dates', () => {
+  it('uses mdy parsing for en-US', () => {
+    setFormatSettings('en-US', 6, 'numeric')
+
+    const result = evalLine('11/22/2005')
+    expect(result.type).toBe('date')
+    expect(result.value).toContain(
+      new Date(2005, 10, 22).toLocaleDateString('en-US'),
+    )
+
+    expectNumericClose('22/11/2005', 22 / 11 / 2005, 6)
+  })
+
+  it('uses dmy parsing for en-GB', () => {
+    setFormatSettings('en-GB', 6, 'numeric')
+
+    const result = evalLine('22/11/2005')
+    expect(result.type).toBe('date')
+    expect(result.value).toContain(
+      new Date(2005, 10, 22).toLocaleDateString('en-GB'),
+    )
+
+    expectNumericClose('11/22/2005', 11 / 22 / 2005, 6)
+  })
+})
+
 describe('rounding', () => {
   it('to 2 dp', () => expectValue('1/3 to 2 dp', '0.33'))
   it('to 5 digits', () => expectValue('pi to 5 digits', '3.14159'))

src/renderer/composables/__tests__/useMathEngine.timezones.test.ts

@@ -103,6 +103,14 @@ describe('time zones', () => {
     expectDateWithYear('2026-03-06 2:30 pm PST in Berlin', '2026')
   })
 
+  it('uses locale-aware full slash date in zoned expressions', () => {
+    setFormatSettings('en-GB', 6, 'numeric')
+
+    const result = evalLine('22/11/2005 PST in Berlin')
+    expect(result.type).toBe('date')
+    expect(result.value).toContain('2005')
+  })
+
   it('Mar 6 2026 PST in Berlin', () => {
     expectDateWithYear('Mar 6 2026 PST in Berlin', '2026')
   })

src/renderer/composables/math-notebook/math-engine/evaluators/dateArithmetic.ts

@@ -8,6 +8,7 @@ import { splitTopLevelAddSub } from '../utils'
 interface DateArithmeticDeps {
   mathEvaluate: (expression: string, scope: Record<string, any>) => any
   formatResult: (result: any) => any
+  locale: string
 }
 
 function evaluateDateLikeExpression(
@@ -16,14 +17,15 @@ function evaluateDateLikeExpression(
   scope: Record<string, any>,
   deps: DateArithmeticDeps,
 ) {
-  const timeZoneResult = evaluateTimeZoneLine(expression, now)
+  const timeZoneResult = evaluateTimeZoneLine(expression, now, deps.locale)
   if (timeZoneResult?.rawResult instanceof Date) {
     return timeZoneResult.rawResult
   }
 
   const localTemporalResult = parseExplicitLocalTemporalExpression(
     expression,
     now,
+    deps.locale,
   )
   if (localTemporalResult) {
     return localTemporalResult.date

src/renderer/composables/math-notebook/math-engine/pipeline/evaluate.ts

@@ -201,11 +201,13 @@ export function evaluateClassifiedLine(
     mathEvaluate: (expression: string, nextScope: Record<string, any>) =>
       math.evaluate(expression, nextScope),
     formatResult,
+    locale: activeLocale,
   }
   return evaluateMathPath(
     trimmed,
     processed,
     currentDate,
+    activeLocale,
     scope,
     math,
     mathDeps,

src/renderer/composables/math-notebook/math-engine/pipeline/evaluateMath.ts

@@ -15,6 +15,7 @@ export function evaluateMathPath(
   trimmed: string,
   processed: string,
   currentDate: Date,
+  locale: string,
   scope: Record<string, any>,
   math: MathEvaluatorInstance,
   mathDeps: MathDeps,
@@ -50,6 +51,7 @@ export function evaluateMathPath(
   const localTemporalResult = parseExplicitLocalTemporalExpression(
     processed,
     currentDate,
+    locale,
   )
   if (localTemporalResult) {
     return toEvaluatedLine(

src/renderer/composables/math-notebook/math-engine/pipeline/evaluateRoutes.ts

@@ -134,6 +134,7 @@ export function evaluatePrimaryIntent(
             mathEvaluate: (expression, nextScope) =>
               math.evaluate(expression, nextScope),
             formatResult,
+            locale: activeLocale,
           },
         )
 
@@ -157,6 +158,7 @@ export function evaluatePrimaryIntent(
           mathEvaluate: (expression, nextScope) =>
             math.evaluate(expression, nextScope),
           formatResult,
+          locale: activeLocale,
         },
       )
 

src/renderer/composables/math-notebook/math-engine/pipeline/evaluateTypes.ts

@@ -41,4 +41,5 @@ export interface EvaluatedLine {
 export interface MathDeps {
   mathEvaluate: (expression: string, scope: Record<string, any>) => any
   formatResult: LineFormatter['formatResult']
+  locale: string
 }