2-is-proper-fraction.js

// Implement a function isProperFraction,
// when given two numbers, a numerator and a denominator, it should return true if
// the given numbers form a proper fraction, and false otherwise.

// Assumption: The parameters are valid numbers (not NaN or Infinity).

// Note: If you are unfamiliar with proper fractions, please look up its mathematical definition.

// Acceptance criteria:
// After you have implemented the function, write tests to cover all the cases, and
// execute the code to ensure all tests pass.

function isProperFraction(numerator, denominator) {
  if( numerator <  denominator) {
    return true;
  }
  else {return false; }

  // TODO: Implement this function
}

// The line below allows us to load the isProperFraction function into tests in other files.
// This will be useful in the "rewrite tests with jest" step.
module.exports = isProperFraction;

// Here's our helper again
function assertEquals(actualOutput, targetOutput) {
  console.assert(
    actualOutput === targetOutput,
    `Expected ${actualOutput} to equal ${targetOutput}`
  );
}

// TODO: Write tests to cover all cases.
// What combinations of numerators and denominators should you test?

// Example: 1/2 is a proper fraction
assertEquals(isProperFraction(1, 2), true);
// inproper fraction:
assertEquals (isProperFraction(5, 3), false );

// equal numbers
assertEquals (isProperFraction(4, 4), false );

// negative numbers
assertEquals (isProperFraction(-2, 4), true );
assertEquals (isProperFraction(5, -4), false );
assertEquals (isProperFraction (-3,-5), false);

// special case
assertEquals(isProperFraction(1,0) , false);

assertEquals (isProperFraction (0,5), true);