The document discusses patterns for more powerful asserts when doing approval testing. It outlines 7 approaches to asserting values in approval tests, moving from simple number and string assertions to more complex objects, files, automatically generated names, custom verification methods, and using diff tools to compare outputs on failure. The goal is to make approval testing more expressive and tests less cluttered while still using normal test scenarios.

1. Common Path for
Approval Testing
patterns for more powerful asserts
@LlewellynFalco

2. English
CodeResult
Whiteboard
// Create side (0,0) – (3,4)
// Verify length
Side s = new Side(0,0,3,4);
Approvals.Verify(s + “ length = “ +s.Length);
Side (0,0) – (3,4) length = 5
Testing Circle

3. 1) Numbers
// verify 2 names
assert(2, names.length)
Easy
Simple

4. 1) Numbers
// verify names
assert(5, names.length)
assert(“Llew”, names[0])
assert(“Woody”, names[1])
assert(“Jim”, names[2])
assert(“Jason”, names[3])
assert(“Dan”, names[4])
Can get
complicated
I have to
change my
Scenarios
to make it work

5. 1. Specification
2. Feedback
3. Regression
4. Granularity

6. 2) Strings
// verify names
Assert(
“[Llew, Woody, Jim, Jason, Dan]”,
names.toString())
More expressive
Objects, Tests & Logs
Can use
your
normal
Scenarios

7. 2) Strings You’ll start to want
more…
// verify names
Assert(
“[Llew, Woody, Jim, Jason, Dan]”,
names.toString())

8. 3)
// verify json
Assert(
“{age:12,
name:Tom,
address: 123 fake st}”,
tom.toString())
Easy to test bigger
concepts
Long
strings

9. 3)
// verify xml
Assert(
“<xml><person>nt<name>tom<name>n
t<age>”13”<age>nt</person>”,
tom.toString())
Can get very bigLong
strings
Line endings
Scoping
Matters
can != should

10. 4) Files
// verify companies as xml
assertFileContains(
“expected.companylist.xml”,
report.toString())
Less Clutter
Can use
your
normal
Scenarios

11. 4) Files
// verify companies as xml
assertFileContains(
“expected.companylist.xml”,
report.toString())
Lots of filenames
Creating
The files

12. 5)
// verify companies as xml
Verify(report)
Convention over
configuration
Code
starts to
become
trivial
Automatic
names

13. 5)
// verify companies as xml
Verify(report)
What went wrong?
Automatic
names

14. Slow
Do
Verify Pass
Increase
Feedback
Fail

15. See the forest
& the trees
Files not
limited to
text
6) Diff Tools
Can render
html, svg, etc…
(on failure)

16. Duplication
in the tests6) Diff Tools
On failure
event is
pretty basic
(on failure)

17. Testing gets
easier & easier7)
Custom Test
Methods
MapReduce.verify(…)
Wpf.verify(…)
Xml.verify(…)
Routing.verify(…)
Tests give
high Return on
Investment

18. 1. Numb3rs
2. “Strings”
3. “VeryrnLongrnStrings”
4. Files.txt
5. AutomaticNames()
6. DIFF TOOLS DIFF T00LS
7. Test.CustomVerify()