Rename symbol with batch changes

[malomarrec]

All credits to @LawnGnome, @eseliger and @mrnugget for coming up with this, crafting presentations and suggesting paths forward.

Context

Today, Batch Changes spreads relatively slowly inside a company and remains used by a limited audience of platform engineers.

Thesis: If we get more users into batch changes through easy-to-use entry points, they will keep using it and some will move to more complicated use cases.

Feature

Use LSIF data to allow users to rename a symbol from a wizard in the code intel popover.

A limitation of this is it requires auto-indexing (or rather it requires LSIF data to be available). But the way we see this is we should not block on auto-indexing adoption to build useful features, rather we should try and make the value of having auto-indexing setup higher.

Delivery plan

Step 1: First, let's prototype this quickly and feature flag it.

• There's a “rename this symbol” in the hover tooltips. All it can do then is renaming all occurrences of that one symbol, potentially across repos for which we have LSIF data.
• When the user clicks on it, the batch changes page opens, with a preloaded spec that contains the position of the symbol to rename, and a placeholder for users to rename
• The spec relies on a pre-bundled container that takes in the reference of the symbol to change, a scope (search query), and the new name of the symbol. See this GraphQL query

Step 2: Will likely be about improving the UI a bit (eg. the symbol new name could be directly input from the popover instead of being changed in the spec).

Later steps will probably be about creating a path that avoids having to see / edit the spec at all (even though users can still tweak it if they want).

Success criteria:

Overall, if this feature is successful, we should see a significant increase of MAUs in the first 3 months of a relevant customer turning it on (at GA).
We can measure more granular success with the # of symbol reaming batch changes created per month.

Analytics

Before we move this to beta, we'll want:

• number of clicks on the "rename symbol"
• number of batch changes previewed as a result
• number of batch changes applied as a result

[malomarrec]

For future work: here's something that is very hard (or impossible) to do with comby:

• Replace len(a)== 0 by a== "" if a is a string

A adjacent version of this that we could probably do relatively easily with batch changes is:

• Rename a to newa if a is a string

[steveyegge]

This is the #1 most common use case of Rosie (Google's batch changes tool).

Java developers never like their symbol names for long.

[eseliger]

Who does, really!

You might like this hackathon loom: https://www.loom.com/share/6285137481c641b18fa0c9dc92d4addd