Output lines are messed up with several tests files

[a14n]

When I use pub run test (with test-0.12.0-beta.10 and Dart 1.10.0-dev.1.9) when several test files are available, the output lines seem not correct (dupplicated or removed).

For instance with the rational package:

$ pub run test:test test/bigint_test.dart 

00:00 +0: string validation                                                           
00:00 +1: string validation                                                           
00:00 +1: valid js int                                                                
00:00 +2: valid js int                                                                
00:00 +2: toString()                                                                  
00:00 +3: toString()                                                                  
00:00 +3: operator ==(BigInt other)                                                   
00:00 +4: operator ==(BigInt other)                                                   
00:00 +4: compareTo(BigInt other)                                                     
00:00 +5: compareTo(BigInt other)                                                     
00:00 +5: operator +(BigInt other)                                                    
00:00 +6: operator +(BigInt other)                                                    
00:00 +6: operator -(BigInt other)                                                    
00:00 +7: operator -(BigInt other)                                                    
00:00 +7: operator *(BigInt other)                                                    
00:00 +8: operator *(BigInt other)                                                    
00:00 +8: operator %(BigInt other)                                                    
00:00 +9: operator %(BigInt other)                                                    
00:00 +9: operator ~/(BigInt other)                                                   
00:00 +10: operator ~/(BigInt other)                                                  
00:00 +10: operator -()                                                               
00:00 +11: operator -()                                                               
00:00 +11: All tests passed!                                                                        

$ pub run test:test test/rational_test.dart 

00:00 +0: string validation                                                           
00:00 +1: string validation                                                           
00:00 +1: parse scientific notation                                                   
00:00 +2: parse scientific notation                                                   
00:00 +2: get isInteger                                                               
00:00 +3: get isInteger                                                               
00:00 +3: operator ==(Rational other)                                                 
00:00 +4: operator ==(Rational other)                                                 
00:00 +4: toDecimalString()                                                           
00:00 +5: toDecimalString()                                                           
00:00 +5: compareTo(Rational other)                                                   
00:00 +6: compareTo(Rational other)                                                   
00:00 +6: operator +(Rational other)                                                  
00:00 +7: operator +(Rational other)                                                  
00:00 +7: operator -(Rational other)                                                  
00:00 +8: operator -(Rational other)                                                  
00:00 +8: operator *(Rational other)                                                  
00:00 +9: operator *(Rational other)                                                  
00:00 +9: operator %(Rational other)                                                  
00:00 +10: operator %(Rational other)                                                 
00:00 +10: operator /(Rational other)                                                 
00:00 +11: operator /(Rational other)                                                 
00:00 +11: operator ~/(Rational other)                                                
00:00 +12: operator ~/(Rational other)                                                
00:00 +12: operator -()                                                               
00:00 +13: operator -()                                                               
00:00 +13: remainder(Rational other)                                                  
00:00 +14: remainder(Rational other)                                                  
00:00 +14: operator <(Rational other)                                                 
00:00 +15: operator <(Rational other)                                                 
00:00 +15: operator <=(Rational other)                                                
00:00 +16: operator <=(Rational other)                                                
00:00 +16: operator >(Rational other)                                                 
00:00 +17: operator >(Rational other)                                                 
00:00 +17: operator >=(Rational other)                                                
00:00 +18: operator >=(Rational other)                                                
00:00 +18: get isNaN                                                                  
00:00 +19: get isNaN                                                                  
00:00 +19: get isNegative                                                             
00:00 +20: get isNegative                                                             
00:00 +20: get isInfinite                                                             
00:00 +21: get isInfinite                                                             
00:00 +21: abs()                                                                      
00:00 +22: abs()                                                                      
00:00 +22: signum                                                                     
00:00 +23: signum                                                                     
00:00 +23: floor()                                                                    
00:00 +24: floor()                                                                    
00:00 +24: ceil()                                                                     
00:00 +25: ceil()                                                                     
00:00 +25: round()                                                                    
00:00 +26: round()                                                                    
00:00 +26: truncate()                                                                 
00:00 +27: truncate()                                                                 
00:00 +27: clamp(Rational lowerLimit, Rational upperLimit)                            
00:00 +28: clamp(Rational lowerLimit, Rational upperLimit)                            
00:00 +28: toInt()                                                                    
00:00 +29: toInt()                                                                    
00:00 +29: toDouble()                                                                 
00:00 +30: toDouble()                                                                 
00:00 +30: toStringAsFixed(int fractionDigits)                                        
00:00 +31: toStringAsFixed(int fractionDigits)                                        
00:00 +31: toStringAsExponential(int fractionDigits)                                  
00:00 +32: toStringAsExponential(int fractionDigits)                                  
00:00 +32: toStringAsPrecision(int precision)                                         
00:00 +33: toStringAsPrecision(int precision)                                         
00:00 +33: hasFinitePrecision                                                         
00:00 +34: hasFinitePrecision                                                         
00:00 +34: precision                                                                  
00:00 +35: precision                                                                  
00:00 +35: scale                                                                      
00:00 +36: scale                                                                      
00:00 +36: All tests passed!                                                                        

$ pub run test:test

00:00 +0: test/rational_test.dart: string validation                                  
00:00 +1: test/rational_test.dart: string validation                                  
00:00 +2: test/rational_test.dart: string validation                                  
00:00 +3: test/bigint_test.dart: toString()                                           
00:00 +4: test/bigint_test.dart: toString()                                           
00:00 +5: test/bigint_test.dart: toString()                                           
00:00 +6: test/bigint_test.dart: toString()                                           
00:00 +7: test/bigint_test.dart: toString()                                           
00:00 +8: test/rational_test.dart: compareTo(Rational other)                          
00:00 +9: test/rational_test.dart: compareTo(Rational other)                          
00:00 +9: test/bigint_test.dart: operator ==(BigInt other)                            
00:00 +10: test/rational_test.dart: operator +(Rational other)                        
00:00 +11: test/bigint_test.dart: compareTo(BigInt other)                             
00:00 +12: test/rational_test.dart: operator -(Rational other)                        
00:00 +13: test/bigint_test.dart: operator +(BigInt other)                            
00:00 +14: test/rational_test.dart: operator *(Rational other)                        
00:00 +15: test/bigint_test.dart: operator -(BigInt other)                            
00:00 +16: test/bigint_test.dart: operator -(BigInt other)                            
00:00 +16: test/rational_test.dart: operator %(Rational other)                        
00:00 +17: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +18: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +19: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +20: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +21: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +22: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +23: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +24: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +25: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +26: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +27: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +28: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +29: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +30: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +31: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +32: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +33: test/bigint_test.dart: operator *(BigInt other)                            
00:00 +34: test/rational_test.dart: truncate()                                        
00:00 +35: test/bigint_test.dart: operator %(BigInt other)                            
00:00 +36: test/bigint_test.dart: operator %(BigInt other)                            
00:00 +37: test/bigint_test.dart: operator %(BigInt other)                            
00:00 +38: test/bigint_test.dart: operator %(BigInt other)                            
00:00 +39: test/bigint_test.dart: operator %(BigInt other)                            
00:00 +40: test/bigint_test.dart: operator %(BigInt other)                            
00:00 +41: test/bigint_test.dart: operator %(BigInt other)                            
00:00 +42: test/bigint_test.dart: operator %(BigInt other)                            
00:00 +42: test/rational_test.dart: hasFinitePrecision                                
00:00 +43: test/bigint_test.dart: operator ~/(BigInt other)                           
00:00 +44: test/bigint_test.dart: operator ~/(BigInt other)                           
00:00 +45: test/bigint_test.dart: operator ~/(BigInt other)                           
00:00 +46: test/bigint_test.dart: operator ~/(BigInt other)                           
00:00 +46: test/bigint_test.dart: operator -()                                        
00:00 +47: test/bigint_test.dart: operator -()                                        
00:00 +47: All tests passed!                                                                        

BTW: I don't really know why but depending on the screen size the pub run test output is either a single line or the above multi-line output. What is the reason ?

[zoechi]

Seems to be similar to google/grinder.dart#194 I run into when I run tests using Grinder.

[nex3]

@a14n

When I use pub run test (with test-0.12.0-beta.10 and Dart 1.10.0-dev.1.9) when several test files are available, the output lines seem not correct (dupplicated or removed).

The runner runs multiple test suites in parallel. This means that there's not a clear linear progression of tests, since multiple tests are running at once and they may overlap, so it has to decide what to print when. The heuristic it uses is simple: it always prints the name of the test that's been running for the longest. This means that quick tests may not show up, and slow tests may show up for longer, but it also produces the least incomprehensible flickering on the command line.

BTW: I don't really know why but depending on the screen size the pub run test output is either a single line or the above multi-line output. What is the reason ?

Single-line output works via the magic of the carriage return or \r character. When printed, this character tells the terminal's cursor to go back to the beginning of the current line; any characters printed afterwards will overwrite those printed previously. This works well if everything fits on one line, but (for many terminals) once the width is too small the \r ends up on the next line, which means that it only goes back to the beginning of that line. This creates the multi-line output you see.

Unfortunately, there's no way (short of C APIs that are inaccessible to Dart) to determine the actual width of the terminal, so we have to just choose a number. The best workaround is to widen your terminal.

[a14n]

Thanks for the explanation.

[nex3]

Unfortunately, there's no way (short of C APIs that are inaccessible to Dart) to determine the actual width of the terminal, so we have to just choose a number. The best workaround is to widen your terminal.

Actually, this may not be true; it looks like most Unix terminals are capable of more advanced manipulation just using escape codes on standard IO. That's worth investigating in the future.

[nex3]

Actually, dart:io's Stdout object has a terminalLines getter. We should just use that to detect how long to make our lines.

[nex3]

Unfortunately, this is blocked on pub run spawning an isolate for its subprocesses.