Uploaded byCristian COȚOI
Writing quick and beautiful automation code
The document provides an introduction to Hamcrest and Lambdaj, two tools useful for writing automation code. Hamcrest focuses on improving clarity and readability in assertions for testing, while Lambdaj simplifies manipulation of collections without explicit loops. It highlights the advantages of both libraries in agile development, including speed and ease of learning.
Writing quick and beautiful automation code
- 1. Writing quick and beautiful automationcode Introduction to Hamcrest and Lambdaj Cristian Coțoi May 20 2013
- 2. •BDD (Agile) hasnew needs •What is hamcrest •What is lambdaj •Improvement Agenda 2
- 3. IN YOUR ZONE Purpose 3 •http://hamcrest.org •“Hamcrestit is not a testing library: it just happens that matchers are very useful for testing.” •Matching allows writing of lines that are close-to natural language •Anagram of “matchers” •http://code.google.com/p/lambdaj/ •Access collections without explicit loops •Operations include: items filtering, converting, sorting, method invoking, concatenate etc. Hamcrest Lambdaj
- 4. IN YOUR ZONE WhyHamcrest 4 •Clarity •assertThat(a, is(“3”)); •assertEquals(a, “3”); •Speed •Not necessarily applicable for isNull() or isNotNull() •assertThat(list, hasItems(“banana”, “paple”, “papoi”));
- 5. IN YOUR ZONE Hamcrest(some of the common matchers) 5 •Core • is •Logical • allOf - like Java && • anyOf - like Java || • not •Object • equalTo - test object equality using Object.equals • notNullValue, nullValue - test for null
- 6. IN YOUR ZONE Hamcrest(some of the common matchers) 6 •Collections • hasEntry, hasKey, hasValue - test a map contains an entry, key or value • hasItem, hasItems - test a collection contains elements •Number • closeTo - test floating point values are close to a given value • greaterThan, greaterThanOrEqualTo, lessThan, lessThanOrEqualTo - test ordering •Text • equalToIgnoringCase • containsString, endsWith, startsWith - test string matching
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- 8. IN YOUR ZONE HamcrestExamples 8 •hasItem, hasItems
- 9. IN YOUR ZONE Hamcrestexamples 9 •hasItems (fail)
- 10. IN YOUR ZONE Hamcrestexamples 10 •hasEntry, hasValue, hasKey
- 11. IN YOUR ZONE Hamcrestexamples 11 •Numbers
- 12. IN YOUR ZONE Hamcrest 12 •Actualautomation code example
- 13. IN YOUR ZONE Lambdaj 13 •It’sdesigned to easily manipulate collections. •It uses Hamcrest matchers for filtering
- 14. IN YOUR ZONE WhyLambdaj 14 •Readability •Collections are very common •Iterating over them is not dead-easy •Loops are hard to read •Operations for collections: Convert, Index, Filter, Sort, Extract etc.
- 15. IN YOUR ZONE Lambdajexamples 15 •Mathematical comparisons •Mathematical operations
- 16. IN YOUR ZONE Lambdajexamples 16 •Method invoke – add last name
- 17. IN YOUR ZONE Lambdajexamples 17 •Select
- 18. IN YOUR ZONE Lambdajexamples 18 •Youngest Papoi
- 19. IN YOUR ZONE Lambdajautomation example 19
- 20. IN YOUR ZONE Lambdajlimitations 20 •Null or empty collection in forEach •Final class
- 21. IN YOUR ZONE Benefits 21 •Integrationwith Agile methodologies (BDD) •Clarity •Speed •Quick learning curve •Extensive application
- 22. IN YOUR ZONE Thankyou 22 Cristian Coțoi| Senior Tester
- 23. IN YOUR ZONE References 23 •Hamcrest •http://code.google.com/p/hamcrest/wiki/Tutorial • http://edgibbs.com/junit-4-with-hamcrest/ • http://rafaelnaufal.com/blog/2010/03/15/using-hamcrest-and-junit/ - writing your own matchers •LambdaJ • http://code.google.com/p/lambdaj/ • http://code.google.com/p/lambdaj/wiki/LambdajFeatures
Editor's Notes
- #3 There is a new trend in BDD that empowers every member of the team to make changes in the code of the application & testing, starting with how the stories are connected with the code and should also be taken deeper.Hamcrest and lambdaj are 2 such libraries that make the code more human readable and easier to understand.
- #5 So why would I want to write assertions like this?ClarityassertThat() is a replacement for the traditionalassertEqual that is focused more on specifications than on BDDFirst one reads: “assert that a is 3”. The second reads “assert equals a (and) 3”SpeedThis is pretty str8 forward: “assert that list contains ‘banana’, ‘paple’, ‘papoi’”
- #15 Collections are hard to interrogate, especially when read from an outside source.It is easy to write a loop, but not so very easy to extract things from that loop or perform conversions or other operations on the items in the loop.
- #18 You can read this like:select from family items having…last nameequal to `Papoi`
- #21 The current implementation of forEach cannot handle null or empty collections – this will just throw an exception.The same is true for a final class that is used with on()On average it is about 2-3 times slower, but depending on the collection it sometimes can be 6 times slower.