Yarn compliance

[kanthesha]

Since the module template uses Yarn v3, we want all projects to conform to the same thing. So, minimally, for this ticket, we want this tool to be able to look a project and verify whether it is using the same version of Yarn as is specified in the module template.

There are several ways to check that the Yarn version conforms, though. If this is the case for a project, then these things will be true:

• The packageManager field in package.json should exist
• The value of the packageManager field should match the same value as the module template
• .yarn/plugins/@yarnpkg/plugin-allow-scripts.cjs should exist, and its contents should match what's in the module template
• .yarn/plugins/@yarnpkg/plugin-constraints.cjs should exist, and its contents should match what's in the module template
• .yarn/releases/yarn-3.2.1.cjs should exist, and its contents should match what's in the module template
• The .yarnrc.yml file should exist, and the contents of this file should match the same file in the module template
• The README should include a line - Install Yarn v3

References

• Closes module-lint: Make sure package.json exists #23
• Closes Add checks for Yarn compliance #11

[mcmire]

Superseded by #39.