Class Assume

java.lang.Object
org.junit.Assume
public class Assume extends Object
A set of methods useful for stating assumptions about the conditions in which a test is meaningful. A failed assumption does not mean the code is broken, but that the test provides no useful information. Assume basically means "don't run this test if these conditions don't apply". The default JUnit runner skips tests with failing assumptions. Custom runners may behave differently.

A good example of using assumptions is in Theories where they are needed to exclude certain datapoints that aren't suitable or allowed for a certain test case.

Failed assumptions are usually not logged, because there may be many tests that don't apply to certain configurations.

These methods can be used directly: Assume.assumeTrue(...), however, they read better if they are referenced through static import:

import static org.junit.Assume.*;
   ...
   assumeTrue(...);

Since:
4.4
See Also:

  • Constructor Details

    • Assume

      @Deprecated public Assume()
      Deprecated.
      since 4.13.
      Do not instantiate.

  • Method Details

    • assumeTrue

      public static void assumeTrue(boolean b)
      If called with an expression evaluating to false, the test will halt and be ignored.

    • assumeFalse

      public static void assumeFalse(boolean b)
      The inverse of assumeTrue(boolean).

    • assumeTrue

      public static void assumeTrue(String message, boolean b)
      If called with an expression evaluating to false, the test will halt and be ignored.
      Parameters:
      message - A message to pass to AssumptionViolatedException.
      b - If false, the method will attempt to stop the test and ignore it by throwing AssumptionViolatedException.

    • assumeFalse

      public static void assumeFalse(String message, boolean b)
      The inverse of assumeTrue(String, boolean).

    • assumeNotNull

      public static void assumeNotNull(Object... objects)
      If called with a null array or one or more null elements in objects, the test will halt and be ignored.

    • assumeThat

      public static <T> void assumeThat(T actual, org.hamcrest.Matcher<T> matcher)
      Call to assume that actual satisfies the condition specified by matcher. If not, the test halts and is ignored. Example: 
      :
  assumeThat(1, is(1)); // passes
  foo(); // will execute
  assumeThat(0, is(1)); // assumption failure! test halts
  int x = 1 / 0; // will never execute
      Type Parameters:
      T - the static type accepted by the matcher (this can flag obvious compile-time problems such as assumeThat(1, is("a"))
      Parameters:
      actual - the computed value being compared
      matcher - an expression, built of Matchers, specifying allowed values
      See Also:

    • assumeThat

      public static <T> void assumeThat(String message, T actual, org.hamcrest.Matcher<T> matcher)
      Call to assume that actual satisfies the condition specified by matcher. If not, the test halts and is ignored. Example: 
      :
  assumeThat("alwaysPasses", 1, is(1)); // passes
  foo(); // will execute
  assumeThat("alwaysFails", 0, is(1)); // assumption failure! test halts
  int x = 1 / 0; // will never execute
      Type Parameters:
      T - the static type accepted by the matcher (this can flag obvious compile-time problems such as assumeThat(1, is("a"))
      Parameters:
      actual - the computed value being compared
      matcher - an expression, built of Matchers, specifying allowed values
      See Also:

    • assumeNoException

      public static void assumeNoException(Throwable e)
      Use to assume that an operation completes normally. If e is non-null, the test will halt and be ignored. For example: 
      \@Test public void parseDataFile() {
  DataFile file;
  try {
    file = DataFile.open("sampledata.txt");
  } catch (IOException e) {
    // stop test and ignore if data can't be opened
    assumeNoException(e);
  }
  // ...
}
      Parameters:
      e - if non-null, the offending exception

    • assumeNoException

      public static void assumeNoException(String message, Throwable e)
      Attempts to halt the test and ignore it if Throwable e is not null. Similar to assumeNoException(Throwable), but provides an additional message that can explain the details concerning the assumption.
      Parameters:
      message - Additional message to pass to AssumptionViolatedException.
      e - if non-null, the offending exception
      See Also: