apacheGH-40718: [JS] Fix set visitor in vectors for js dates

domoritz · Mar 21, 2024 · a197751 · a197751
1 parent 27cea44
commit a197751
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Showing 2 changed files with 17 additions and 8 deletions.
diff --git a/js/src/visitor/set.ts b/js/src/visitor/set.ts
@@ -108,21 +108,21 @@ function wrapSet<T extends DataType>(fn: (data: Data<T>, _1: any, _2: any) => vo
 }
 
 /** @ignore */
-export const setEpochMsToDays = (data: Int32Array, index: number, epochMs: number) => { data[index] = Math.trunc(epochMs / 86400000); };
+export const setEpochMsToDays = (data: Int32Array, index: number, epochMs: number) => { data[index] = Math.floor(epochMs / 86400000); };
 /** @ignore */
 export const setEpochMsToMillisecondsLong = (data: Int32Array, index: number, epochMs: number) => {
-    data[index] = Math.trunc(epochMs % 4294967296);
-    data[index + 1] = Math.trunc(epochMs / 4294967296);
+    data[index] = Math.floor(epochMs % 4294967296);
+    data[index + 1] = Math.floor(epochMs / 4294967296);
 };
 /** @ignore */
 export const setEpochMsToMicrosecondsLong = (data: Int32Array, index: number, epochMs: number) => {
-    data[index] = Math.trunc((epochMs * 1000) % 4294967296);
-    data[index + 1] = Math.trunc((epochMs * 1000) / 4294967296);
+    data[index] = Math.floor((epochMs * 1000) % 4294967296);
+    data[index + 1] = Math.floor((epochMs * 1000) / 4294967296);
 };
 /** @ignore */
 export const setEpochMsToNanosecondsLong = (data: Int32Array, index: number, epochMs: number) => {
-    data[index] = Math.trunc((epochMs * 1000000) % 4294967296);
-    data[index + 1] = Math.trunc((epochMs * 1000000) / 4294967296);
+    data[index] = Math.floor((epochMs * 1000000) % 4294967296);
+    data[index + 1] = Math.floor((epochMs * 1000000) / 4294967296);
 };
 
 /** @ignore */

diff --git a/js/test/unit/vector/date-vector-tests.ts b/js/test/unit/vector/date-vector-tests.ts
@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-import { DateDay, DateMillisecond, RecordBatchReader, Table } from 'apache-arrow';
+import { DateDay, DateMillisecond, RecordBatchReader, Table, vectorFromArray } from 'apache-arrow';
 
 describe(`DateVector`, () => {
     it('returns days since the epoch as correct JS Dates', () => {
@@ -27,6 +27,7 @@ describe(`DateVector`, () => {
             expect(date).toEqual(millis === null ? null : new Date(millis!));
         }
     });
+
     it('returns millisecond longs since the epoch as correct JS Dates', () => {
         const table = new Table(RecordBatchReader.from(test_data));
         const expectedMillis = expectedMillis64();
@@ -36,6 +37,14 @@ describe(`DateVector`, () => {
             expect(date).toEqual(millis === null ? null : new Date(millis!));
         }
     });
+
+    it('returns the same date that was in the vector', () => {
+        const dates = [new Date(1950, 1, 0)];
+        const vec = vectorFromArray(dates);
+        for (const date of vec) {
+            expect(date).toEqual(dates.shift());
+        }
+    });
 });
 
 const expectedMillis32 = () => [