MR Process: Prevent many git checkout opperations when unneeded

[zepumph]

This has been biting @jonathanolson during his current maintenance release, for example, here is the current implementation of ReleaseBranch.usesChipper2():

    async usesChipper2() {
      await gitCheckout( this.repo, this.branch );
      const dependencies = await getDependencies( this.repo );
      await gitCheckout( 'chipper', dependencies.chipper.sha );

      const chipperVersion = ChipperVersion.getFromRepository();

      const result = chipperVersion.major !== 0 || chipperVersion.minor !== 0;

      await gitCheckout( this.repo, 'main' );
      await gitCheckout( 'chipper', 'main' );

      return result;
    }

Gross! Why does it need to checkout so many branches?!?!?! Let's try to reduce that so that ReleaseBranches can multitask better.

[zepumph]

@jonathanolson and I came to a solution that uses git cat-file blob. This is working really well in testing, and I think it would be a nice improvement for many, many usages of gitCheckout in perennial/js/common.

[zepumph]

I got to a commit point, but right now I'm just adjusting ReleaseBranch.usesChipper2(). More to come if we don't run into trouble.

Here is how I tested things:

( async () => {

  // TEST ONE
  const ReleaseBranch = require( '../perennial/js/common/ReleaseBranch' );

  const rb12 = new ReleaseBranch( 'acid-base-solutions', '1.2', [ 'phet' ], true );
  const rb13 = new ReleaseBranch( 'acid-base-solutions', '1.3', [ 'phet' ], true );
  console.log( 'acid-base-solutions 1.2 uses chipper 2.0: ', await rb12.usesChipper2() ); // -> false
  console.log( 'acid-base-solutions 1.3 uses chipper 2.0: ', await rb13.usesChipper2() ); // -> true


  /// TEST TWO
  const assert = require( 'assert' );
  const _ = require( 'lodash' );
  const gitCatFile = require( '../perennial/js/common/gitCatFile' );
  const gitCheckout = require( '../perennial/js/common/gitCheckout' );
  const loadJSON = async ( repo, file, branch ) => {
    return JSON.parse( await gitCatFile( repo, file, branch ) );
  };

  // acid base solutions
  // git checkout d1b56e98e01bec64769402037ef60e1e81f90b00
  const testSHA = 'd1b56e98e01bec64769402037ef60e1e81f90b00';
  await gitCheckout( 'acid-base-solutions', testSHA );

  const defaultHEADDependencies = await loadJSON( 'acid-base-solutions', 'dependencies.json' );
  const currentSHADependencies = await loadJSON( 'acid-base-solutions', 'dependencies.json', testSHA );
  const mainDependencies = await loadJSON( 'acid-base-solutions', 'dependencies.json', 'main' );

  assert( _.isEqual( defaultHEADDependencies, currentSHADependencies ) );
  assert( defaultHEADDependencies[ 'acid-base-solutions' ].sha !== mainDependencies[ 'acid-base-solutions' ].sha );
  await gitCheckout( 'acid-base-solutions', 'main' );

  // TEST THREE
  console.log( ( await gitCatFile( 'density-buoyancy-common', 'js/density/model/DensityIntroModel.ts', 'density-1.1' ) ).length, 'DensityIntroModel file chars on density-1.1 branch' );
  console.log( ( await gitCatFile( 'density-buoyancy-common', 'js/density/model/DensityIntroModel.ts' ) ).length, 'DensityIntroModel file chars on main branch' );
} )();

[zepumph]

@jonathanolson please report any trouble you find.

[zepumph]

@jonathanolson mentioned that we are already doing this with getFileFromBranch So likely this issue is moot, and we can get rid of gitCatFile.

[zepumph]

@samreid and I found another spot for improvement here:

perennial/js/common/Maintenance.js

Line 836 in be6a53d

await checkoutTarget( modifiedBranch.repo, modifiedBranch.branch, false );

• Instead of checking out everything for updateDependencies, I believe we could just look at the modifiedBranch.changedDependencies and only checkout those + the releaseBranch repo.

[zepumph]

@samreid had a nice thought where we could just ask github directly in certain cases instead of needing to thrash with checkouts and pulls. I don't know if this is totally possible (like to support credentials for private repos etc), but here is a possible way to prevent as many checkouts

// Ensure you're using Node.js v18 or later
// You can check your Node.js version by running `node -v` in your terminal

// Define an asynchronous function to fetch and parse JSON
async function fetchDependencies( sim, branch ) {

  const response = await fetch( `[https://raw.githubusercontent.com/phetsims/${sim}/refs/heads/${branch}/dependencies.json](https://raw.githubusercontent.com/phetsims/$%7Bsim%7D/refs/heads/$%7Bbranch%7D/dependencies.json)` );

  // Check if the response status is OK (status code 200-299)
  if ( !response.ok ) {
    throw new Error( `Network response was not ok. Status: ${response.status} ${response.statusText}` );
  }

  // Parse the response as JSON
  const data = await response.json();
  console.log( data );
}

// Call the function
fetchDependencies( 'density', '1.2' );