add error margins

Signed-off-by: Utkarsh Srivastava <srivastavautkarsh8097@gmail.com>

Author: tangledbytes

tests/generateUniqueID.ts

@@ -12,6 +12,7 @@ describe("Snowflake with default configuration", () => {
   });
 
   it("should return timestamp of creation", () => {
+    const ERROR_MARGIN = 2;
     const uid = new UniqueID();
 
     const before = Date.now(); // Before calling
@@ -20,7 +21,7 @@ describe("Snowflake with default configuration", () => {
 
     const ts = uid.getTimestampFromID(id);
 
-    expect(ts).to.be.greaterThanOrEqual(before).and.lessThanOrEqual(after);
+    expect(ts).to.be.greaterThanOrEqual(before - ERROR_MARGIN).and.lessThanOrEqual(after + ERROR_MARGIN);
   });
 
   it("should return machine id", () => {
@@ -62,6 +63,7 @@ describe("Snowflake with custom machine ID configuration", () => {
   });
 
   it("should return timestamp of creation", () => {
+    const ERROR_MARGIN = 2
     const uid = new UniqueID({ machineID: 1000 });
 
     const before = Date.now(); // Before calling
@@ -70,7 +72,7 @@ describe("Snowflake with custom machine ID configuration", () => {
 
     const ts = uid.getTimestampFromID(id);
 
-    expect(ts).to.be.greaterThanOrEqual(before - 1).and.lessThanOrEqual(after + 1);
+    expect(ts).to.be.greaterThanOrEqual(before - ERROR_MARGIN).and.lessThanOrEqual(after + ERROR_MARGIN);
   });
 
   it("should return current machine's id from the generated id", () => {