1. An Empirical Study of Popularity and
Quality of NPM Packages
1
Ahmed Zerouali

2. Motivation
2
Number of libaries in most known OS package managers
- 206k libraries - Java
- 162k packages - PHP
- 600k packages - JavaScript
In 10/Nov/2017

3. Motivation
3
Reasons to choose the right OS software:
 Software Quality
 Software Features
 Software Support and Documentation
 Software Popularity
 …
 …

4. Motivation
4
Choosing the right OS software:
 Software Quality
 Software Features
 Software Support and Documentation
 Software Popularity
 …
 …

5. Motivation
5
Interviews with developers:
 C. Bogart, C. Kästner, J. Herbsleb, and F. Thung. How to break
an API: Cost negotiation and community values in three software
ecosystems. In Int’l Symp. Foundations of Software Engineering
(FSE), pages 109–120. ACM, 2016.
Popularity and community reputation are the most influenced factors.

6. Motivation
6
Software Popularity and Quality
TOP 14

7. Motivation
7
Software Popularity and Quality
TOP 2

8. Method
8
Chosen software package manager

9. Method
9
An open source repository containing
metadata(size, dependents,
dependencies) of package
dependencies extracted from 23
package managers.
An open source search engine that
computes a normalized score between 0
and 1 of the npm packages popularity,
quality and maintenance

10. Method
10
characteristics score
Popularity Quality Maintenance
# stars
# forks
# subscribers
#contributors
# dependents
# downloads
# Downloads
acceleration
README?
License?
.gitignore and friends?
Has tests?
#Test coverage
Is the build passing?
#outdated deps
& vulnerabilities?
Has Custom website?
Has Linters Configured?
#Ratio of open issues
vs. total issues
#Time to close issues
#Commits frequency
#Release frequency

11. Data Extraction
11
- Download the prepared and availabale
metadata from 15th June 2017
- Use API and get the latest information
( rate limit= 60 request/minute )
-Use API (no rate limit)

12. Method
12
DESCRIPTIVE STATISTICS OF THE CONSIDERED DATASET

13. Research Questions
13
RQ0(preliminary question): How are measures of package
popularity related to the use of a package?
RQ1: Is there a relationship between package quality
and package popularity?
RQ2: Is there a relationship between the maintainability
and popularity of packages?
RQ3: Are deprecated packages still being used?
RQ4: How different are packages used in web frontend
development in the context of all packages?

14. Data Analysis
14
-Data analysis and precessing: import pandas
- Data visualization: import matplotlib
import seaborn
- Analytics: import scipy

15. RQ0 - How are measures of package popularity
related to the use of a package?
15
Pearson correlation coefficient R= 0.8

16. RQ0 - How are measures of package popularity
related to the use of a package?
16
 Almost 4 out of 10 packages are not used by any other package or
external repository.
 35% of packages don’t have any direct dependency
package

17. RQ1 - Is there a relationship between package quality
and package popularity?
17
- Quality
- Testing (tests, test converage, build status)
- Carefulness( licence, readme, .gitingor..).
- Health ( outdated dependencies and
vulnerabilities)
-Branding( badges and homepage)
- Popularity
-Community interest (npms.io)
- dependent external repositories (libraries.io)

18. RQ1 - Is there a relationship between package quality
and package popularity?
18
Distribution of popularity in terms of community interest, number of dependent
repositories and quality score of npm packages, split into packages that have at
least one dependency and packages that don’t.

19. RQ1 - Is there a relationship between package quality
and package popularity?
19
Pearson correlation coefficient R <0.33, for both testing and carefulness

20. RQ2 - Is there a relationship between the
maintainability and popularity of packages?
20
Distribution of maintenance characteristics scores grouped in packages
that have a commit score above the median and packages that have a commit
score under the median(0.25)

21. RQ2 - Is there a relationship between the
maintainability and popularity of packages?
21

22. RQ3: Are deprecated packages still being used?
22
- Package declared ‘deprecated’ in the status: 768
- Packages declared ‘deprecated’ in the description: 1,522
Total deprecated packages found: 2,290( out of all npm)
 Total deprecated packages found in npmsio: 836

23. RQ3: Are deprecated packages still being used?
23
0.4% of all npm packages are deprecated packages and they are
less used.
Deprecated packages are used by popular packages too.
Deprecated packages have the same characteristics as the other
packages, except for size, release frequency, commit frequency and
fixing issues.

24. RQ4: How different are packages used in web
frontend development in the context of all packages?
24
- Package on Bower : 65,397
- Package on Bower and npm : 25,203
 Total front-end packages found in npmsio: 20,210

25. RQ4: How different are packages used in web
frontend development in the context of all packages?
25

26. Limitations
26
-Npms.io and libraries.io metrics and their evaluation.
- Not generalizable to other packages.
- Package category.

27. Conclusion
27
 Investigated the relationship between software popularity and quality.
Used npms.io and libraries.io.
Found that:
Software popularity and quality are weakly correlated.
Maintenance has little impact on Popularity.
 Only a small number of packages are deprecated.
 Front-end packages are more popular.

28. Future Work
28
- Cross-ecosystem comparisons: detect differences in the
relation between popularity and quality across ecosystems.
-Qualitative analysis: carrying out interviews and surveys
with package developers.

29. 29

30. Questions
30