[WIP] Fix CI Git logic

[roryabraham]

This PR fixes some flaws we've got with our existing git logic for cherry-picks.

Problem Details

Some of the Git logic we use to cherry-pick changes to staging is fundamentally flawed. A great resource to understand this problem is this article, especially parts 1-5. (h\t @oldnewthing, this article was very helpful).

Our scenario is a bit different than the one described in the article, so I did my best to draw it up, along with the 3-way merge chart for the problematic merge:

3-way merge chart

Solution Details

Here's a diagram showing the solution I got from the article and applied to our situation, along with the new 3-way-merge chart:

3-way merge chart

Fixed Issues

$ #10214

Tests

• Verify that no errors appear in the JS console

PR Review Checklist

Contributor (PR Author) Checklist

• I linked the correct issue in the ### Fixed Issues section above
• I wrote clear testing steps that cover the changes made in this PR
  • I added steps for local testing in the Tests section
  • I added steps for Staging and/or Production testing in the QA steps section
  • I added steps to cover failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
  • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline)
• I included screenshots or videos for tests on all platforms
• I ran the tests on all platforms & verified they passed on:
  • iOS / native
  • Android / native
  • iOS / Safari
  • Android / Chrome
  • MacOS / Chrome
  • MacOS / Desktop
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I followed proper code patterns (see Reviewing the code)
  • I verified that any callback methods that were added or modified are named for what the method does and never what callback they handle (i.e. toggleReport and not onIconClick)
  • I verified that comments were added to code that is not self explanatory
  • I verified that any new or modified comments were clear, correct English, and explained "why" the code was doing something instead of only explaining "what" the code was doing.
  • I verified any copy / text shown in the product was added in all src/languages/* files
  • I verified any copy / text that was added to the app is correct English and approved by marketing by tagging the marketing team on the original GH to get the correct copy.
  • I verified proper file naming conventions were followed for any new files or renamed files. All non-platform specific files are named after what they export and are not named "index.js". All platform-specific files are named for the platform the code supports as outlined in the README.
  • I verified the JSDocs style guidelines (in STYLE.md) were followed
• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I followed the guidelines as stated in the Review Guidelines
• I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
• I verified all code is DRY (the PR doesn't include any logic written more than once, with the exception of tests)
• I verified any variables that can be defined as constants (ie. in CONST.js or at the top of the file that uses the constant) are defined as such
• If a new component is created I verified that:
  • A similar component doesn't exist in the codebase
  • All props are defined accurately and each prop has a /** comment above it */
  • Any functional components have the displayName property
  • The file is named correctly
  • The component has a clear name that is non-ambiguous and the purpose of the component can be inferred from the name alone
  • The only data being stored in the state is data necessary for rendering and nothing else
  • For Class Components, any internal methods passed to components event handlers are bound to this properly so there are no scoping issues (i.e. for onClick={this.submit} the method this.submit should be bound to this in the constructor)
  • Any internal methods bound to this are necessary to be bound (i.e. avoid this.submit = this.submit.bind(this); if this.submit is never passed to a component event handler like onClick)
  • All JSX used for rendering exists in the render method
  • The component has the minimum amount of code necessary for its purpose, and it is broken down into smaller components in order to separate concerns and functions
• If a new CSS style is added I verified that:
  • A similar style doesn't already exist
  • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(themeColors.componentBG)
• If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
• If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
• I have checked off every checkbox in the PR author checklist, including those that don't apply to this PR.

PR Reviewer Checklist

The Contributor+ will copy/paste it into a new comment and complete it after the author checklist is completed

• I have verified the author checklist is complete (all boxes are checked off).
• I verified the correct issue is linked in the ### Fixed Issues section above
• I verified testing steps are clear and they cover the changes made in this PR
  • I verified the steps for local testing are in the Tests section
  • I verified the steps for Staging and/or Production testing are in the QA steps section
  • I verified the steps cover any possible failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
  • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline)
• I checked that screenshots or videos are included for tests on all platforms
• I verified tests pass on all platforms & I tested again on:
  • iOS / native
  • Android / native
  • iOS / Safari
  • Android / Chrome
  • MacOS / Chrome
  • MacOS / Desktop
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I verified proper code patterns were followed (see Reviewing the code)
  • I verified that any callback methods that were added or modified are named for what the method does and never what callback they handle (i.e. toggleReport and not onIconClick).
  • I verified that comments were added to code that is not self explanatory
  • I verified that any new or modified comments were clear, correct English, and explained "why" the code was doing something instead of only explaining "what" the code was doing.
  • I verified any copy / text shown in the product was added in all src/languages/* files
  • I verified any copy / text that was added to the app is correct English and approved by marketing by tagging the marketing team on the original GH to get the correct copy.
  • I verified proper file naming conventions were followed for any new files or renamed files. All non-platform specific files are named after what they export and are not named "index.js". All platform-specific files are named for the platform the code supports as outlined in the README.
  • I verified the JSDocs style guidelines (in STYLE.md) were followed
• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I verified that this PR follows the guidelines as stated in the Review Guidelines
• I verified other components that can be impacted by these changes have been tested, and I retested again (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar have been tested & I retested again)
• I verified all code is DRY (the PR doesn't include any logic written more than once, with the exception of tests)
• I verified any variables that can be defined as constants (ie. in CONST.js or at the top of the file that uses the constant) are defined as such
• If a new component is created I verified that:
  • A similar component doesn't exist in the codebase
  • All props are defined accurately and each prop has a /** comment above it */
  • Any functional components have the displayName property
  • The file is named correctly
  • The component has a clear name that is non-ambiguous and the purpose of the component can be inferred from the name alone
  • The only data being stored in the state is data necessary for rendering and nothing else
  • For Class Components, any internal methods passed to components event handlers are bound to this properly so there are no scoping issues (i.e. for onClick={this.submit} the method this.submit should be bound to this in the constructor)
  • Any internal methods bound to this are necessary to be bound (i.e. avoid this.submit = this.submit.bind(this); if this.submit is never passed to a component event handler like onClick)
  • All JSX used for rendering exists in the render method
  • The component has the minimum amount of code necessary for its purpose, and it is broken down into smaller components in order to separate concerns and functions
• If a new CSS style is added I verified that:
  • A similar style doesn't already exist
  • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(themeColors.componentBG)
• If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
• If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
• I have checked off every checkbox in the PR reviewer checklist, including those that don't apply to this PR.

QA Steps

• Verify that no errors appear in the JS console

Screenshots

Web

Mobile Web

Desktop

iOS

Android

[roryabraham]

We used to pass this token to try and set up git as OSBotify. I don't think it ever really worked, but in any event it's not necessary because in the next step we call setupGitForOSBotify.

[roryabraham]

Fetching all history so we don't need to do a separate fetch later

[roryabraham]

This is more concise syntax for what used to be the Save correct NEW_VERSION to env step

[roryabraham]

Need to dig in to confirm, but I think there won't be conflicts against the temporary branch created from the merge-base of the two commits we're trying to CP.

I think the merge conflicts will pop up when we're attempting to merge code into staging (and even then, only if there are multiple conflicting CPs)

[roryabraham]

This was a pretty weird workaround – we were literally committing the conflicts including the ====HEAD==== stuff, and asking people to overwrite that.

Fortunately, I don't think we'll really need to do this anymore. Instead, we'll CP the commits into a temporary branch which won't have any conflicts, then create the PR. If the PR has merge conflicts, then it will be unmergeable and we'll assign someone to resolve those conflicts. However, it will appear like a normal PR with merge conflicts listed at the bottom of the page. None of the wonky ====HEAD==== stuff will be committed into the files.

[roryabraham]

I think we are going to go another route with this. Going to close this out for now