Unsing Java's Supplier interface to facilitate mock behavior for unit tests
up vote
0
down vote
favorite
I recently had to refactor a class [X] and improve its unit test and in doing so discovered that in order to get full coverage of the class from the tests I was going to need to mock out the behaviour of 3 different components of the class. For arguments sake classes [A], [B] and [C]. Because [A], [B] & [C] were all constructed within [X] I decided to pass in a Supplier for each of them allowing the unit test to mock the Supplier and enable complete test coverage of the class.
However a colleague of mine suggested instead that I could have added package visible getter methods for each of [A], [B] & [C] to deal with the object construction and then override these from the unit test when creating the instance of [X] to be tested.
I can see that this removes the extra complication of adding the Supplier implementations but I feel this exposes the implementation of [X] unnecessarily. Is one of these approaches considered to substantially better than the other? The project I'm working on uses Spring which I'm not too familiar with, but I'm wondering if there might be a better solution with that.
Does anyone have some solid advice on this?
java spring unit-testing supplier
asked Nov 12 at 16:14
Chris Danson
122313
add a comment |
up vote
0
down vote
favorite
I recently had to refactor a class [X] and improve its unit test and in doing so discovered that in order to get full coverage of the class from the tests I was going to need to mock out the behaviour of 3 different components of the class. For arguments sake classes [A], [B] and [C]. Because [A], [B] & [C] were all constructed within [X] I decided to pass in a Supplier for each of them allowing the unit test to mock the Supplier and enable complete test coverage of the class.
However a colleague of mine suggested instead that I could have added package visible getter methods for each of [A], [B] & [C] to deal with the object construction and then override these from the unit test when creating the instance of [X] to be tested.
I can see that this removes the extra complication of adding the Supplier implementations but I feel this exposes the implementation of [X] unnecessarily. Is one of these approaches considered to substantially better than the other? The project I'm working on uses Spring which I'm not too familiar with, but I'm wondering if there might be a better solution with that.
Does anyone have some solid advice on this?
java spring unit-testing supplier
asked Nov 12 at 16:14
Chris Danson
122313
2
Why would you even need a supplier, just use dependency injection into the constructor instead.
– M. Deinum
Nov 12 at 16:17
thanks -- I've been introduced to Spring a couple of days ago and have just started familiarizing.
– Chris Danson
Nov 12 at 16:19
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I recently had to refactor a class [X] and improve its unit test and in doing so discovered that in order to get full coverage of the class from the tests I was going to need to mock out the behaviour of 3 different components of the class. For arguments sake classes [A], [B] and [C]. Because [A], [B] & [C] were all constructed within [X] I decided to pass in a Supplier for each of them allowing the unit test to mock the Supplier and enable complete test coverage of the class.
However a colleague of mine suggested instead that I could have added package visible getter methods for each of [A], [B] & [C] to deal with the object construction and then override these from the unit test when creating the instance of [X] to be tested.
I can see that this removes the extra complication of adding the Supplier implementations but I feel this exposes the implementation of [X] unnecessarily. Is one of these approaches considered to substantially better than the other? The project I'm working on uses Spring which I'm not too familiar with, but I'm wondering if there might be a better solution with that.
Does anyone have some solid advice on this?
java spring unit-testing supplier
asked Nov 12 at 16:14
Chris Danson
122313
I recently had to refactor a class [X] and improve its unit test and in doing so discovered that in order to get full coverage of the class from the tests I was going to need to mock out the behaviour of 3 different components of the class. For arguments sake classes [A], [B] and [C]. Because [A], [B] & [C] were all constructed within [X] I decided to pass in a Supplier for each of them allowing the unit test to mock the Supplier and enable complete test coverage of the class.
However a colleague of mine suggested instead that I could have added package visible getter methods for each of [A], [B] & [C] to deal with the object construction and then override these from the unit test when creating the instance of [X] to be tested.
I can see that this removes the extra complication of adding the Supplier implementations but I feel this exposes the implementation of [X] unnecessarily. Is one of these approaches considered to substantially better than the other? The project I'm working on uses Spring which I'm not too familiar with, but I'm wondering if there might be a better solution with that.
Does anyone have some solid advice on this?
java spring unit-testing supplier
java spring unit-testing supplier
asked Nov 12 at 16:14
Chris Danson
122313
asked Nov 12 at 16:14
Chris Danson
122313
asked Nov 12 at 16:14
Chris Danson
122313
asked Nov 12 at 16:14
Chris Danson
122313
asked Nov 12 at 16:14
Chris Danson
122313
122313
2
Why would you even need a supplier, just use dependency injection into the constructor instead.
– M. Deinum
Nov 12 at 16:17
thanks -- I've been introduced to Spring a couple of days ago and have just started familiarizing.
– Chris Danson
Nov 12 at 16:19
add a comment |
2
Why would you even need a supplier, just use dependency injection into the constructor instead.
– M. Deinum
Nov 12 at 16:17
thanks -- I've been introduced to Spring a couple of days ago and have just started familiarizing.
– Chris Danson
Nov 12 at 16:19
2
2
Why would you even need a supplier, just use dependency injection into the constructor instead.
– M. Deinum
Nov 12 at 16:17
Why would you even need a supplier, just use dependency injection into the constructor instead.
– M. Deinum
Nov 12 at 16:17
thanks -- I've been introduced to Spring a couple of days ago and have just started familiarizing.
– Chris Danson
Nov 12 at 16:19
thanks -- I've been introduced to Spring a couple of days ago and have just started familiarizing.
– Chris Danson
Nov 12 at 16:19
add a comment |
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53266073%2funsing-javas-supplier-interface-to-facilitate-mock-behavior-for-unit-tests%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
active
oldest
votes
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53266073%2funsing-javas-supplier-interface-to-facilitate-mock-behavior-for-unit-tests%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
2
Why would you even need a supplier, just use dependency injection into the constructor instead.
– M. Deinum
Nov 12 at 16:17
thanks -- I've been introduced to Spring a couple of days ago and have just started familiarizing.
– Chris Danson
Nov 12 at 16:19