Only infer strings as timestamps if they are within 2 years of the current date

Author: ericallam

src/formats/timestamp.ts

@@ -7,26 +7,49 @@ const timestampSecondsSinceEpoch = /^\d{10}$/;
 const timestampMsSinceEpoch = /^\d{13}$/;
 const timestampNanoSinceEpoch = /^\d{19}$/;
 
+// If the msSinceEpoch is within 2 years of the current time, then inRangeOfNow will be true
+function inRangeOfNow(msSinceEpoch: number): boolean {
+  const now = new Date().getTime();
+  const acceptableRange = 2 * 365 * 24 * 60 * 60 * 1000;
+
+  const lowerBound = msSinceEpoch - acceptableRange;
+  const upperBound = msSinceEpoch + acceptableRange;
+
+  return now >= lowerBound && now <= upperBound;
+}
+
 export function inferTimestamp(value: string): JSONTimestampFormat | undefined {
   if (timestampSecondsSinceEpoch.test(value)) {
-    return {
-      name: "timestamp",
-      variant: "secondsSinceEpoch",
-    };
+    const seconds = parseInt(value);
+
+    if (inRangeOfNow(seconds * 1000)) {
+      return {
+        name: "timestamp",
+        variant: "secondsSinceEpoch",
+      };
+    }
   }
 
   if (timestampMsSinceEpoch.test(value)) {
-    return {
-      name: "timestamp",
-      variant: "millisecondsSinceEpoch",
-    };
+    const milliseconds = parseInt(value);
+
+    if (inRangeOfNow(milliseconds)) {
+      return {
+        name: "timestamp",
+        variant: "millisecondsSinceEpoch",
+      };
+    }
   }
 
   if (timestampNanoSinceEpoch.test(value)) {
-    return {
-      name: "timestamp",
-      variant: "nanosecondsSinceEpoch",
-    };
+    const nanoseconds = parseInt(value);
+
+    if (inRangeOfNow(nanoseconds / 1000000)) {
+      return {
+        name: "timestamp",
+        variant: "nanosecondsSinceEpoch",
+      };
+    }
   }
 
   return undefined;

tests/stringFormats.test.ts

@@ -813,10 +813,13 @@ describe("credit cards", () => {
 });
 
 describe("without format", () => {
-  test.each(["46"])("%p should be inferred as having no format", (value) => {
-    expect(inferType(value)).toEqual({
-      name: "string",
-      value,
-    });
-  });
+  test.each(["46", "2244994945", "1212092628029698048"])(
+    "%p should be inferred as having no format",
+    (value) => {
+      expect(inferType(value)).toEqual({
+        name: "string",
+        value,
+      });
+    },
+  );
 });