TruncDivTest.java

package com.hubspot.jinjava.el.ext;

import static org.assertj.core.api.Assertions.assertThat;
import static org.junit.Assert.assertEquals;

import com.google.common.collect.Maps;
import com.hubspot.jinjava.Jinjava;
import com.hubspot.jinjava.interpret.FatalTemplateErrorsException;
import com.hubspot.jinjava.interpret.RenderResult;
import com.hubspot.jinjava.interpret.TemplateError;
import com.hubspot.jinjava.interpret.TemplateError.ErrorReason;
import com.hubspot.jinjava.interpret.TemplateError.ErrorType;
import java.util.HashMap;
import java.util.Map;
import org.junit.Before;
import org.junit.Test;

public class TruncDivTest {
  private Jinjava jinja;

  @Before
  public void setUp() {
    jinja = new Jinjava();
  }

  /**
   * Test the truncated division operator "//" with integer values
   */
  @Test
  public void testTruncDivInteger() {
    Map<String, Object> context = Maps.newHashMap();
    context.put("dividend", 5);
    context.put("divisor", 2);
    context.put("negativeDividend", -5);
    context.put("negativeDivisor", -2);
    context.put("zeroDivisor", 0);

    String[][] testCases = {
      { "{% set x = dividend // divisor %}{{x}}", "2" },
      { "{% set x = 5 // 2 %}{{x}}", "2" },
      { "{% set x = dividend // 2 %}{{x}}", "2" },
      { "{% set x = 5 // divisor %}{{x}}", "2" },
      { "{% set x = negativeDividend // divisor %}{{x}}", "-3" },
      { "{% set x = -5 // 2 %}{{x}}", "-3" },
      { "{% set x = dividend // negativeDivisor %}{{x}}", "-3" },
      { "{% set x = 5 // -2 %}{{x}}", "-3" },
      { "{% set x = negativeDividend // negativeDivisor %}{{x}}", "2" },
      { "{% set x = -5 // -2 %}{{x}}", "2" }
    };

    for (String[] testCase : testCases) {
      String template = testCase[0];
      String expected = testCase[1];
      String rendered = jinja.render(template, context);
      assertEquals(expected, rendered);
    }
  }

  /**
   * Test the truncated division operator "//" with divisor equal to zero
   */
  @Test
  public void testTruncDivZeroDivisor() {
    final String intTestCase = "{% set x = 10 // 0%}{{x}}";
    final String doubleTestCase = "{% set x = 10 // 0.0%}{{x}}";
    final String[] testCases = { intTestCase, doubleTestCase };

    for (String testCase : testCases) {
      RenderResult result = jinja.renderForResult(testCase, new HashMap<>());

      assertEquals(result.getErrors().size(), 1);
      TemplateError error = result.getErrors().get(0);
      assertEquals(error.getSeverity(), ErrorType.FATAL);
      assertEquals(error.getReason(), ErrorReason.EXCEPTION);
      assertEquals(
        error.getMessage().contains("Divisor for // (truncated division) cannot be zero"),
        true
      );
    }
  }

  /**
   * Test the truncated division operator "//" with fractional values
   */
  @Test
  public void testTruncDivFractional() {
    Map<String, Object> context = Maps.newHashMap();
    context.put("dividend", 5.0);
    context.put("divisor", 2);
    context.put("negativeDividend", -5.0);
    context.put("negativeDivisor", -2);

    String[][] testCases = {
      { "{% set x = dividend // divisor %}{{x}}", "2.0" },
      { "{% set x = 5.0 // 2 %}{{x}}", "2.0" },
      { "{% set x = dividend // 2 %}{{x}}", "2.0" },
      { "{% set x = 5.0 // divisor %}{{x}}", "2.0" },
      { "{% set x = negativeDividend // divisor %}{{x}}", "-3.0" },
      { "{% set x = -5.0 // 2 %}{{x}}", "-3.0" },
      { "{% set x = dividend // negativeDivisor %}{{x}}", "-3.0" },
      { "{% set x = 5.0 // -2 %}{{x}}", "-3.0" },
      { "{% set x = negativeDividend // negativeDivisor %}{{x}}", "2.0" },
      { "{% set x = -5.0 // -2 %}{{x}}", "2.0" }
    };

    for (String[] testCase : testCases) {
      String template = testCase[0];
      String expected = testCase[1];
      String rendered = jinja.render(template, context);
      assertEquals(expected, rendered);
    }
  }

  /**
   * Test the truncated division operator "//" with strings
   */
  @Test
  public void testTruncDivStringFails() {
    Map<String, Object> context = Maps.newHashMap();
    context.put("dividend", "5");
    context.put("divisor", "2");

    String template = "{% set x = dividend // divisor %}";
    try {
      jinja.render(template, context);
    } catch (FatalTemplateErrorsException e) {
      assertThat(e.getMessage())
        .contains("Unsupported operand type(s) for //: '5' (String) and '2' (String)");
    }
  }
}