Merge pull request #434 from vil02/4892_prohibit_calling_createIntInR…

…ange_with_empty_range

Prohibit calling `createIntInRange` with empty range

ballerina/natives.bal

@@ -41,7 +41,7 @@ public isolated function createDecimal() returns float {
 # + endRange - Range end value
 # + return - Selected random value or else, a `random:Error` if the start range is greater than the end range
 public isolated function createIntInRange(int startRange, int endRange) returns int|Error {
-    if startRange > endRange {
+    if startRange >= endRange {
         return error Error("End range value must be greater than the start range value");
     }
     return <int>(lcg() / m * (<decimal>(endRange - 1) - <decimal>startRange) + <decimal>startRange);

ballerina/tests/random.bal

@@ -31,6 +31,17 @@ isolated function createIntInRangeTest() {
     }
 }
 
+@test:Config {}
+isolated function createIntInRangeWithSingleElementTest() {
+    final int someInt = 123;
+    int|error result = createIntInRange(someInt, someInt + 1);
+    if result is int {
+        test:assertTrue(result == someInt, msg = "createIntInRangeWithSingleElementTest result is not " + someInt.toString());
+    } else {
+        test:assertFail("createIntInRangeTest result is not int");
+    }
+}
+
 @test:Config {}
 isolated function negativeTestforCreateIntInRangeTest() {
     int|error result = createIntInRange(5000, 10);
@@ -42,6 +53,17 @@ isolated function negativeTestforCreateIntInRangeTest() {
     }
 }
 
+@test:Config {}
+isolated function negativeTestforCreateIntInRange2Test() {
+    int|error result = createIntInRange(17, 17);
+    if result is error {
+        test:assertTrue(result.message().includes("End range value must be greater than the start range value"),
+                    msg = "negativeTestforCreateIntInRange2Test result incorrect");
+    } else {
+        test:assertFail("Result is not mismatch");
+    }
+}
+
 @test:Config {}
 isolated function doesNotThrowForFullIntRangeTest() {
     int|error result = createIntInRange(int:MIN_VALUE, int:MAX_VALUE);

changelog.md

@@ -9,6 +9,7 @@ This file contains all the notable changes done to the Ballerina TCP package thr
 
 - [Make `createIntInRange` work for full int range ](https://github.com/ballerina-platform/ballerina-standard-library/issues/4744)
 - [Remove duplicated codecov badge](https://github.com/ballerina-platform/ballerina-standard-library/issues/4893)
+- [Prohibit calling `createIntInRange` with empty range](https://github.com/ballerina-platform/ballerina-standard-library/issues/4892)
 
 ## [1.5.0] - 2023-09-15