Migrating explicit-any takes far longer than I expected

[Cactice]

[explicit-any] Finished in 1h 32m 5.3s.
.
.
.
Finished in 1h 48m 32.9s, for 14 plugin(s).

At the end there were 47 files that were updated. Most of which were less than 200 lines.
lines = 200x14=2800
seconds to finish=92x60=5520
seconds per line = 5520/2280 = 2.42s

This is a very rough estimate but hopefully this information is helpful for anybody worried if there's something wrong with explicit-any.

Please note that it may take a long time to do a full migration.

This is helpful but given most of the other plugins finished in less than a few minutes,
I was expecting 10-20 min for explicit-any but this took way longer than that so I thought there was something wrong with the plugin.

[Cactice]

I will close this.
I just wanted to leave a note for those who were worried if explicit-any is stuck or is just very slow.

[edsrzf]

I think it's worth leaving this open. It doesn't sound right.

Are you able to share any more details about your project that might help us figure out the cause?

[Cactice]

I can't share the full code/repo but I noticed an issue with the renaming process.
It renamed .js-> .ts file, when it should have renamed .js -> .tsx file.
As a result it was leaving lots of invalid comments // on valid React JSX syntax.
Example:

  return (
    // @ts-expect-error ts-migrate(2749) FIXME: 'MenuWrapper' refers to a value, but is being used... Remove this comment to see the full error message
    <MenuWrapper>
      // @ts-expect-error ts-migrate(2749) FIXME: 'MainMenu' refers to a value, but is being used as... Remove this comment to see the full error message
      <MainMenu>
        // @ts-expect-error ts-migrate(2304) FIXME: Cannot find name 'div'.
        <div className="mx-auto">
          // @ts-expect-error ts-migrate(2749) FIXME: 'Component' refers to a value, but is being used a... Remove this comment to see the full error message
          <Component {...pageProps} />
        </div>
      </MainMenu>

I had to manually revert the changes to .ts files, rename them to .tsx and rerun migration for those files.

Mac OS: v10.15.7
Node: v15.8.0
ts-migrate: 0.1.19 to rename, took too long for the full migration and switched to 0.1.15 to see if it helped which took 1.5 hours to finish.

[edsrzf]

Strange, this sounds like it could be a limitation in the jsFileContainsJsx function in the rename command:

ts-migrate/packages/ts-migrate/commands/rename.ts

Lines 116 to 119 in e852a1e

	function jsFileContainsJsx(jsFileName: string): boolean {
	const contents = fs.readFileSync(jsFileName, 'utf8');
	return /(from ['"]react['"]|@jsx)/.test(contents) && /<[A-Za-z>]/.test(contents);
	}

(It does look a little brittle, to be fair.)

Do you import React using require, perhaps? Or maybe you use the new JSX transform that doesn't require importing React?

[tervay]

Also seeing this using the React 17 JSX transform that does not require importing React (explicit-any took 90 minutes). I think @edsrzf seems to have the best clue into why with jsFileContainsJsx.