fix(tables): keep leading-zero codes as text when inferring CSV column types (#9754)

Author: waleedlatif1

apps/sim/lib/table/import.test.ts

@@ -63,6 +63,17 @@ describe('import', () => {
       )
       expect(columns.map((c) => c.name)).toEqual(['a_b', 'a_b_2', 'a_b_3'])
     })
+
+    it('keeps codes with a leading zero as text so the zero survives', () => {
+      const { columns } = inferSchemaFromCsv(
+        ['zip', 'ratio'],
+        [
+          { zip: '02134', ratio: '0.5' },
+          { zip: '10001', ratio: '0' },
+        ]
+      )
+      expect(columns.map((c) => c.type)).toEqual(['string', 'number'])
+    })
   })
 
   describe('coerceValue', () => {

apps/sim/lib/table/import.ts

@@ -388,9 +388,11 @@ export function inferColumnType(values: unknown[]): InferredCsvColumnType {
   const nonEmpty = values.filter((v) => v !== null && v !== undefined && v !== '')
   if (nonEmpty.length === 0) return 'string'
 
+  // A leading zero before another digit marks a code (ZIP, phone, SKU), not a
+  // quantity: storing it as a number would drop the zero for good.
   const allNumber = nonEmpty.every((v) => {
-    const n = Number(v)
-    return !Number.isNaN(n) && String(v).trim() !== ''
+    const s = String(v).trim()
+    return s !== '' && !Number.isNaN(Number(s)) && !/^[+-]?0\d/.test(s)
   })
   if (allNumber) return 'number'