CODEWITHSUNDEEP
junit
αƞjiβ
αƞjiβ

Reputation: 3246

Assert key in hashmap JUnit

I thought it was going to be easy but can anyone tell me how I can test HashMap to see if it has some value in JUnit?

assertThat(myMap, ??);

I tried something like:

assertThat(myMap, hasEntry("Key", notNullValue()));

...But I couldn't make it compile since my import to hasEntry and notNullValue() is correct. Does anyone know what the correct import pkg for them should be?

Upvotes: 5

Views: 21521

Answers (4)

Helder Pereira
Helder Pereira

Reputation: 5756

I don't like the assertTrue approaches, because the feedback is quite limited when the assertion fails.

It can be done with assertThat like this:

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.hasEntry;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.notNullValue;


assertThat(myMap, hasEntry(is("Key"), notNullValue()));

Upvotes: 0

khelwood
khelwood

Reputation: 59146

To check the key is in the map:

import static org.junit.Assert.assertTrue;
...
assertTrue(myMap.containsKey("Key"));

Alternatively, to check it has a non-null value:

import static org.junit.Assert.assertNotNull;
...
assertNotNull(myMap.get("Key"));

Upvotes: 0

Joe
Joe

Reputation: 31087

You're after hasEntry(Matcher<? super K> keyMatcher, Matcher<? super V> valueMatcher).

The underlying implementation is in IsMapContaining but, like most matchers in Hamcrest, it can also be found through org.hamcrest.Matchers, in hamcrest-library.

Otherwise, your syntax is correct, and Matchers also defines notNullValue().

Upvotes: 3

Cesar Villasana
Cesar Villasana

Reputation: 687

import static org.junit.Assert.AssertTrue;

assertTrue(myMap.containsKey("yourKey") && myMap.get("yourKey") != null)

Upvotes: 3

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