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Photo by Christian Pfeifer on Unsplash

Maxi Contieri⭐⭐⭐
·Mar 2, 2023·

• Problems
• Solutions
• Context
• Sample Code
• Detection
• Tags
• Conclusion
• Relations
• Disclaimer
• Credits

# Solutions

1. Be declarative and explicit

2. Don't oversimplify

# Context

Hidden assumptions are underlying beliefs or expectations not explicitly stated in the code.

They are still present and can impact the behavior of the software.

Various reasons can give rise to assumptions such as incomplete requirements, incorrect presumptions about the user or environment, limitations of the programming language or tools, and bad accidental decisions.

# Sample Code

## Wrong

``````tenCentimeters = 10
tenInches = 10

tenCentimeters + tenInches
# 20
# this error is based on the hidden assumption of a unit (any)
# and caused the Mars Climate Orbiter failure
``````

## Right

``````class Unit:
def __init__(self, name, symbol):
self.name = name
self.symbol = symbol

class Measure:
def __init__(self, scalar, unit):
self.scalar = scalar
self.unit = unit

def __str__(self):
return f"{self.scalar} {self.unit.symbol}"

centimetersUnit = Unit("centimeters", "cm")
inchesUnit = Unit("inches", "in")

tencCentimeters = Measure(10, centimeters)
tenInches = Measure(10, inches)

tenCentimeters + tenInches
# error until we introduce a conversion factor
# in this case the conversion is constant
# inches = centimeters / 2.54
``````

# Detection

[X] Manual

This is a design smell

• Coupling

# Conclusion

Hidden assumptions can be difficult to identify and can lead to bugs, security vulnerabilities, and usability issues.

To mitigate these risks, software developers should be aware of their assumptions and biases.

Developers also need to engage with users to understand their needs and expectations.

They must test their software in various scenarios to uncover hidden assumptions and edge cases.

# Relations

Mars Climate Orbiter Disaster

Measure Solution

# Disclaimer

Code Smells are my opinion.

# Credits

Photo by Christian Pfeifer on Unsplash

A human organization is just as much an information system as any computer system. It is almost certainly more complex, but the same fundamental ideas apply. Things that are fundamentally difficult, like concurrency and coupling, are difficult in the real world of people, too.

Dave Farley