This patch uniformizes warning messages. I used the most common style
already present in the code base:
* Capitalize the first word.
* End the message with a full stop.
* "Rails 5" instead of "Rails 5.0".
* Backticks for method names and inline code.
Also, converted a few long strings into the new heredoc convention.
Performance optimization: `yield` with an implicit `block` is faster than `block.call`.
See http://youtu.be/fGFM_UrSp70?t=10m35s and the following benchmark:
```ruby
require 'benchmark/ips'
def fast
yield
end
def slow(&block)
block.call
end
Benchmark.ips do |x|
x.report('fast') { fast{} }
x.report('slow') { slow{} }
end
# => fast 154095 i/100ms
# => slow 71454 i/100ms
# =>
# => fast 7511067.8 (±5.0%) i/s - 37445085 in 4.999660s
# => slow 1227576.9 (±6.8%) i/s - 6145044 in 5.028356s
```
Since we want this flag to be enabled anytime we are running the tests
under JRuby, let's enable this at the Rakefile level so people get the
performance boost on their local checkout.
Moreover, we avoid having to update this particular line anytime the
option changes on the JRuby side.
The only drawback is that we have to define it in every Rakefile but
there's no big deal, this is already the case for other options.
Right now BenchmarkCleaner allocates hundreds of strings on every request with an exception. This patch moves those strings to be generated at boot once and re-used.
## Bench Methods
I took a modified form of CodeTriage https://github.com/schneems/codetriage-ko1-test-app/blob/master/perf.rake and ran given rake tasks with and without the patch to BacktraceCleaner.
I made an endpoint results in exception
```
def index
raise “foo"
end
```
The gem `memory_profiler` was used to capture objects allocated for a single request. Then `benchmark/ips` was used to test the speed of the patch.
You will see that we use less objects and the code becomes measurably faster with this patch.
## With patch:
Memory for one request:
```
Total allocated 7441
Total retained 37
```
Requests per second:
```
Calculating -------------------------------------
ips 4 i/100ms
-------------------------------------------------
ips 43.0 (±4.7%) i/s - 216 in 5.037733s
```
## Without patch:
Memory used for one request:
```
Total allocated 11599
Total retained 35
```
Requests per second:
```
Calculating -------------------------------------
ips 3 i/100ms
-------------------------------------------------
ips 39.4 (±7.6%) i/s - 198 in 5.052783s
```
## Analysis
The patch is faster:
```
(43.0 - 39.4 ) / 39.4 * 100
# => 9 # % ~ speed bump
```
It also allocates less objects:
```
11599 - 7441
# => 4158
```
These strings are allocated on __EVERY SINGLE REQUEST__. This patch saves us 4158 objects __PER REQUEST__ with exception.
Faster errors == Faster applications
fixture_path is a class attribute of ActiveSupport::TestCase, so
ActiveSupport::TestCase.method_defined?(:fixture_path=) would always
return false.
This should fix#4971
