Dear Maven maintainers,
we are studying Maven dependency specifications and we would like to offer several possible improvements for Maven. (1) The scope management of Maven is complicated and hard to distinguish. Maven maintained 6 scopes (i.e., compile, runtime, provided, system, test, and import). Compare to newer package managers such as NPM, which only has two scopes (i.e., dependencies, devdependencies), Maven has too many types of scopes, which makes it more difficult for users to understand. We went over all POMs on the Maven Central (around 8M artifacts, collected in March 2022) and count the frequency of all types of scope. Some of the scopes are rarely used. Only 0.35% of POMs in the Maven Center used system scope. Also, system scope is similar to provided scope, and import scope can hardly be regarded as a dependency scope. We suggest simplifying the types of scopes by merging system into provided and removing import. (2) In the documentation of Default Artifact Handlers (https://maven.apache.org/ref/3.9.3/maven-core/artifact-handlers.html), type and classifier should introduce more commonly used values as their default value to provide better examples. We found that the default values are rarely used and are not good examples for users to understand the use of the settings. Setting commonly used values as default can help users understand the usage of the settings. We went over all POMs on the Maven Central (around 8M artifacts, collected in March 2022) and count the frequency of all possible values of classifier and type. According to our research, in classifier, the default values have low frequencies, including tests (1.05%), javadoc (0.35%), sources (0.29%), and client(0.01%). More commonly used values are features (1.20%), linux-x86_64 (0.34%), and osx-x86_64 (0.27%). As for type, the top default values are pom (4.38%), test-jar (2.85%), war (1.08%) and the rest of the values are all below 0.1%. Other common examples are esa (2.53%), zip (1.88%), and xml (1.31%). Regards, NTU CSL
