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![Example
Experiment
Array Sum
Experiment
Result
Example Code
> const sum = require('./sum-science')
undefined
> sum([1, 2, 3])
6
> Experiment candidate matched the control
{ context: {}, result: 'value: 6' }](https://image.slidesharecdn.com/02-code-galoso-170910055339/75/Change-Software-Like-a-Scientist-44-2048.jpg)
!['use strict';
const science = require('scientist/console');
const helloWorldConcat = (name) => {
return 'Hello world, ' + name;
};
const helloWorldJoin = (name) => {
return ['Hello world, ‘].join(‘');
};
const helloWorld = (name) => {
return science('helloWorld', (experiment) => {
experiment.use(() => helloWorldConcat(name));
experiment.try(() => helloWorldJoin(name));
});
};
module.exports = helloWorld;
Example
Experiment
Exercise](https://image.slidesharecdn.com/02-code-galoso-170910055339/75/Change-Software-Like-a-Scientist-45-2048.jpg)
!['use strict';
const science = require('scientist/console');
const helloWorldConcat = (name) => {
return 'Hello world, ' + name;
};
const helloWorldJoin = (name) => {
return ['Hello world, ‘, name].join('');
};
const helloWorld = (name) => {
return science('helloWorld', (experiment) => {
experiment.use(() => helloWorldConcat(name));
experiment.try(() => helloWorldJoin(name));
});
};
module.exports = helloWorld;
Example
Experiment
Exercise](https://image.slidesharecdn.com/02-code-galoso-170910055339/75/Change-Software-Like-a-Scientist-46-2048.jpg)
Uploaded byAtlassian
Change Software Like a Scientist
The document discusses the inevitability of software changes due to factors like maintenance and improvements, emphasizing the importance of safe practices for deploying updates. It highlights the role of experiments in software development, using examples from GitHub's Scientist library to demonstrate how to test different implementations and manage side effects. The document underscores the critical need for quality assurance and bug fixes while ensuring that changes do not introduce new issues.
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Change Software Like a Scientist
- 1. Change Software Like aScientist FRED GALOSO | GROWTH ENGINEER, TRELLO | ATLASSIAN | @WAYOUTMIND
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- 12. How does itwork now?Fix it. Apply changes. Don’t break anything. Good luck!
- 13. How does itwork now?Fix it. Apply changes. Don’t break anything. Good luck!
- 14. “List of SoftwareBugs” FIX IT
- 16. Therac-25 radiation therapymachine code is directly responsible for at least five patient deaths in the 1980s when it administered excessive X-rays. SOFTWARE BUGS
- 20. How do we safely changesoftware?
- 21. How do we safely refactorsoftware?
- 22. Tests Code Review Specifications Quality Assurance Safe/ContinuousDeployment Practices … Oh my!
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- 25. Program testing canbe used to show the presence of bugs, but never to show their absence DR. EDSGER W. DIJKSTRA
- 26. Since software hasbugs, given enough time and volume, your data will have bugs, too. JESSE TOTH, GITHUB
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- 28. Measure Twice, CutOver Once
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- 32. def pullable_by?(user) science "repository.pullable-by"do | experiment| experiment.context :repo => id, :user => user.id experiment.use { is_collaborator?(user) } experiment.try { has_access?(user) } end end http://githubengineering.com/scientist/ GitHub: Scientist (Ruby)
- 33. def pullable_by?(user) science "repository.pullable-by"do | experiment| experiment.context :repo => id, :user => user.id experiment.use { is_collaborator?(user) } experiment.try { has_access?(user) } end end http://githubengineering.com/scientist/ GitHub: Scientist (Ruby)
- 34. def pullable_by?(user) science "repository.pullable-by"do | experiment| experiment.context :repo => id, :user => user.id experiment.use { is_collaborator?(user) } experiment.try { has_access?(user) } end end http://githubengineering.com/scientist/ GitHub: Scientist (Ruby)
- 35. def pullable_by?(user) science "repository.pullable-by"do | experiment| experiment.context :repo => id, :user => user.id experiment.use { is_collaborator?(user) } experiment.try { has_access?(user) } end end http://githubengineering.com/scientist/ GitHub: Scientist (Ruby)
- 39. Atwood’s Law: anyapplication that can be written in JavaScript, will eventually be written in JavaScript JEFF ATWOOD
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- 41. git clone https://bitbucket.org/ fredgaloso/code-like-a-scientist.git cdcode-like-a-scientist/examples npm install node —-harmony Example Experiment Example Code Array Sum Experiment Result
- 42. 'use strict'; const sum= (arr) => { let sum = 0; for (var i of arr) { sum += i; } return sum; }; module.exports = sum; Example Experiment Experiment Result Array Sum Example Code
- 43. Example Experiment Array Sum Result Experiment Example Code 'usestrict'; const science = require('scientist/console'); const iterative = (arr) => { let sum = 0; for (var i of arr) { sum += i; } return sum; }; const functional = (arr) => { return arr.reduce((a, b) => { return a + b }); }; const sum = (arr) => { return science('sum', (experiment) => { experiment.use(() => iterative(arr)); experiment.try(() => functional(arr)); }); }; module.exports = sum;
- 44. Example Experiment Array Sum Experiment Result Example Code >const sum = require('./sum-science') undefined > sum([1, 2, 3]) 6 > Experiment candidate matched the control { context: {}, result: 'value: 6' }
- 45. 'use strict'; const science= require('scientist/console'); const helloWorldConcat = (name) => { return 'Hello world, ' + name; }; const helloWorldJoin = (name) => { return ['Hello world, ‘].join(‘'); }; const helloWorld = (name) => { return science('helloWorld', (experiment) => { experiment.use(() => helloWorldConcat(name)); experiment.try(() => helloWorldJoin(name)); }); }; module.exports = helloWorld; Example Experiment Exercise
- 46. 'use strict'; const science= require('scientist/console'); const helloWorldConcat = (name) => { return 'Hello world, ' + name; }; const helloWorldJoin = (name) => { return ['Hello world, ‘, name].join(''); }; const helloWorld = (name) => { return science('helloWorld', (experiment) => { experiment.use(() => helloWorldConcat(name)); experiment.try(() => helloWorldJoin(name)); }); }; module.exports = helloWorld; Example Experiment Exercise
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- 52. Isolation Instrumentation Sideeffect Scientific Side Effects
- 53. Scientific Side Effects Modifying Data Fetching Data Dependencies functionprocessUser(user) { # Isolation const oldDateCalculation = complexDateCreator.create(); const newDateCalculation = new Date(); # Instrumentation const dateProcessed = science('datedProcessed', (experiment) => { experiment.use(() => oldDateCalculation); experiment.try(() => newDateCalculation); }); # Side effect user.lastProcessed = dateProcessed; user.save(); return user; }
- 54. Scientific Side Effects Modifying Data FetchingData Dependencies function getUserById(userId) { const user = science('getUserById', (experiment) => { experiment.use(() => Users.findById(userId)); experiment.try(() => { SQL(‘SELECT * FROM Users WHERE id = %s’, userId)); } }); return user; }
- 55. Scientific Side Effects Modifying Data FetchingData Dependencies function applyBrakes(userId) { const brakeThreshold = science(‘brakeThreshold', (experiment) => { experiment.use(() => ExistingProximityRadar.getBrakeThreshold()); experiment.try(() => NewHybridComputerVisionAndRadar.getBrakeThreshold()); }); return activateBrakes(brakeThreshold); }
- 56. TRELLO ENTERPRISE CASESTUDY Critical Component Authentication Variability Different implementations of SAML standard Maintenance Ensure bug fixes do not cause regressions
- 57. Isolation Authentication API Instrumentation Compare result of oldvs new and improved library Side effect Authenticate user and create session Scientific Side Effects
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- 61. Loose coupling iseven harder.
- 63. Thank you! FRED GALOSO| GROWTH ENGINEER, TRELLO | ATLASSIAN | @WAYOUTMIND