Download as PDF, PPTX
![Typical examples
# Untested guard clauses
return unless Features.wiki_ed?
# Unused scopes
class Revision < ActiveRecord::Base
scope :after_date, ->(date) { where('date > ?', date) }
end
# Untested edge cases
siblings = (parent = opts[:parent]) && parent.children](https://image.slidesharecdn.com/slides-180607135802/75/Deep-into-Ruby-Code-Coverage-17-2048.jpg)
![Under the Hood - DeepCover
$counter[0]+=1; a = 1
$counter[1]+=1; b = 2; c = 3
$counter[2]+=1; d = b + c
$counter[3]+=1; puts d](https://image.slidesharecdn.com/slides-180607135802/75/Deep-into-Ruby-Code-Coverage-28-2048.jpg)
![Under the Hood - DeepCover
$counter[0]+=1; a = 1
$counter[1]+=1; b = 2; $counter[2]+=1; c = 3
$counter[3]+=1; d = b + c
$counter[4]+=1; puts d](https://image.slidesharecdn.com/slides-180607135802/75/Deep-into-Ruby-Code-Coverage-29-2048.jpg)
![Under the Hood - DeepCover
$counter[0]+=1; a = 1
b = 2; c = 3
d = b + c; $counter[1]+=1;
puts d;](https://image.slidesharecdn.com/slides-180607135802/75/Deep-into-Ruby-Code-Coverage-30-2048.jpg)
![Rewriting rules - actually most complex case
obj.a, b, obj.c = [...]
# becomes
# ???](https://image.slidesharecdn.com/slides-180607135802/75/Deep-into-Ruby-Code-Coverage-34-2048.jpg)
![Rewriting rules - actually most complex case
obj.a, b, obj.c = [...]
# becomes
(tracker += 1; obj).a, b,
(tracker2 += 1; obj).c = [...]; tracker3 += 1](https://image.slidesharecdn.com/slides-180607135802/75/Deep-into-Ruby-Code-Coverage-35-2048.jpg)
![Where can control flow be interrupted?
require "active_support/core_ext/object/try"
module DateAndTime
module Calculations
WEEKEND_DAYS = [ 6, 0 ]
def on_weekend?
WEEKEND_DAYS.include?(wday)
end
def all_day
beginning_of_day..end_of_day
end
def end_of_week(start_day = Date.beginning_of_week)
# ...
end
alias :at_end_of_week :end_of_week
end
end](https://image.slidesharecdn.com/slides-180607135802/75/Deep-into-Ruby-Code-Coverage-37-2048.jpg)
Deep into Ruby Code Coverage
- 4.
- 5.
- 6. How - Method Coverage def foo(something: false) ifsomething bar end end # no test Method coverage: 0%
- 7. How - Line Coverage def foo(something: false) ifsomething bar end end # test: expect(foo).to... Method coverage: 100% Line coverage: 75%
- 8. How - Node Coverage def foo(something: false) barif something end # test: expect(foo).to... Method coverage: 100% Line coverage: 100% Node coverage: 80%
- 9. How - Branch coverage def foo(something: false) barif something end # test: expect(foo(something: true)).to...
- 10. How - Branch coverage def foo(something: false) barif something fail_unless_bar_was_run end # test: expect(foo(something: true)).to... Method coverage: 100% Line coverage: 100% Node coverage: 100% Branch coverage: 50%
- 11.
- 12.
- 13.
- 14.
- 15.
- 16.
- 17. Typical examples # Untested guardclauses return unless Features.wiki_ed? # Unused scopes class Revision < ActiveRecord::Base scope :after_date, ->(date) { where('date > ?', date) } end # Untested edge cases siblings = (parent = opts[:parent]) && parent.children
- 20. DeepCover vs MRI Feature MRI DeepCover Line coveragepartial ✓ Node coverage no ✓ Branch coverage partial ✓ Method coverage ✓ ~ Slowdown < 1% ~20% Platform support Ruby 2.5+Ruby 2.1+, JRuby
- 21. DeepCover vs MRI Branch coverage MRIDeepCover if / unless / ?: ✓✓ case / when ✓ ✓ ❘❘ / && no ✓ foo&.bar ✓ ✓ {❘foo = 42, bar: 43❘} no ✓ while / until ✓ !
- 22.
- 23.
- 24. Under the Hood - MRI static int iseq_compile_each0(rb_iseq_t *iseq,LINK_ANCHOR *const ret, ...) { const int line = (int)nd_line(node); const enum node_type type = nd_type(node); if (ISEQ_COMPILE_DATA(iseq)->last_line == line) { /* ignore */ } else { if (node->flags & NODE_FL_NEWLINE) { ISEQ_COMPILE_DATA(iseq)->last_line = line; ADD_TRACE_LINE_COVERAGE(ret, line); ADD_TRACE(ret, RUBY_EVENT_LINE); } } // ... ADD_TRACE_LINE_COVERAGE: same API as TracePoint, just not acccessible from Ruby.
- 25. Under the Hood - MRI // ... switch (type){ case NODE_BLOCK:{ while (node && nd_type(node) == NODE_BLOCK) { CHECK(COMPILE_(ret, "BLOCK body", node->nd_head, (node->nd_next ? 1 : popped))); node = node->nd_next; } if (node) { CHECK(COMPILE_(ret, "BLOCK next", node->nd_next, popped)); } break; } case NODE_IF: case NODE_UNLESS: CHECK(compile_if(iseq, ret, node, popped, type)); break; … 1600 more lines…
- 26. Under the Hood - MRI ; a =1 b = 2; c = 3 d = b + c puts d
- 27. Under the Hood - MRI ADD_TRACE_LINE_COVERAGE; a =1 ADD_TRACE_LINE_COVERAGE; b = 2; c = 3 ADD_TRACE_LINE_COVERAGE; d = b + c ADD_TRACE_LINE_COVERAGE; puts d
- 28. Under the Hood - DeepCover $counter[0]+=1; a =1 $counter[1]+=1; b = 2; c = 3 $counter[2]+=1; d = b + c $counter[3]+=1; puts d
- 29. Under the Hood - DeepCover $counter[0]+=1; a =1 $counter[1]+=1; b = 2; $counter[2]+=1; c = 3 $counter[3]+=1; d = b + c $counter[4]+=1; puts d
- 30. Under the Hood - DeepCover $counter[0]+=1; a =1 b = 2; c = 3 d = b + c; $counter[1]+=1; puts d;
- 31.
- 32. Rewriting rules puts 'Hello' # becomes temp= puts 'hello'; tracker += 1 ; temp
- 33. Rewriting rules - most complex case foo&.bar # becomes temp =foo if nil != temp branch_tracker += 1 temp = temp&.bar tracker += 1 temp end
- 34. Rewriting rules - actually most complex case obj.a, b, obj.c= [...] # becomes # ???
- 35. Rewriting rules - actually most complex case obj.a, b, obj.c= [...] # becomes (tracker += 1; obj).a, b, (tracker2 += 1; obj).c = [...]; tracker3 += 1
- 36. Where can control flow be interrupted? foo = 1 bar= 2 puts(foo + bar)
- 37. Where can control flow be interrupted? require "active_support/core_ext/object/try" module DateAndTime moduleCalculations WEEKEND_DAYS = [ 6, 0 ] def on_weekend? WEEKEND_DAYS.include?(wday) end def all_day beginning_of_day..end_of_day end def end_of_week(start_day = Date.beginning_of_week) # ... end alias :at_end_of_week :end_of_week end end
- 38.
- 39.