Resolving highlight client from firstload - attempt 2 (#4958)

## Summary

<!--
Ideally, there is an attached GitHub issue that will describe the "why".

If relevant, use this section to call out any additional information
you'd like to _highlight_ to the reviewer.
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This is another attempt at
#4851, which had to be
[reverted](#4950) because it
broke type declarations. 😞

TypeScript isn't planning to officially support import path rewriting in
declarations (see
microsoft/TypeScript#31643 (comment)),
so to fully support arbitrary path remappings (like the ones to
`@highlight-run/client`), the most promising solution I could find
involved a combination of
[ttypescript](https://github.com./cevek/ttypescript),
[ts-transform-paths](https://github.com./zerkalica/zerollup/tree/master/packages/ts-transform-paths),
and
[rollup-plugin-typescript2](https://github.com./ezolenko/rollup-plugin-typescript2).

However in our case, we're only looking to remap a single reference, so
a dumb script that looks for the reference and replaces them feels like
a much simpler & lower risk solution. That's what I added in this PR in
addition to the previously reverted changes.

Let me know if y'all would prefer looking into the other approach
instead, which might be worthwhile if we wanted to start using arbitrary
path remappings in libraries (say, to be able use absolute imports
everywhere).

## How did you test this change?

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Frontend - Leave a screencast or a screenshot to visually describe the
changes.
-->

I ran `yarn build && yarn typegen` in both main and this branch, and ran
`diff -rq` to compare both dist folders. There were no differences in
any of the .d.ts files (indicating the import replacement script gave us
the correct output), and the only differences were in `index.js`,
`indexESM.js`, and their respective importmaps, due to the changes in
the package.json file that ends up getting bundled.

![Screenshot 2023-04-12 at 4 43 37
PM](https://user-images.githubusercontent.com/6934200/231610022-ac690d7c-860b-419b-ba96-1287e296b491.png)

## Are there any deployment considerations?

<!--
 Backend - Do we need to consider migrations or backfilling data?
-->

This time I did make sure to include type declarations in the build
output comparison, so I have pretty high confidence they'll behave
identically this time.

Though one thing I couldn't confirm was whether the CI process that
publishes this module runs the `yarn typegen` command or `yarn tsc`
directly. The latter could produce the same problematic output as before
since we depend on the script specified in `yarn typegen` to rewrite
imports. Would appreciate it if someone could double check. 🙏

Author: lewisl9029

Diff for: sdk/firstload/package.json

@@ -6,7 +6,7 @@
 		"dev": "rollup -c -w",
 		"enforce-size": "size-limit",
 		"test": "vitest --run",
-		"typegen": "tsc"
+		"typegen": "tsc && node scripts/replace-client-imports.mjs"
 	},
 	"main": "dist/index.js",
 	"module": "dist/indexESM.js",
@@ -20,6 +20,7 @@
 		"@size-limit/file": "^8.1.0",
 		"@types/chrome": "^0.0.144",
 		"esbuild": "^0.14.47",
+		"readdirp": "^3.6.0",
 		"rollup": "^2.79.1",
 		"rollup-plugin-consts": "^1.1.0",
 		"rollup-plugin-esbuild": "^4.9.1",

Diff for: sdk/firstload/rollup.config.js

@@ -22,7 +22,19 @@ const basePlugins = [
 	consts({
 		publicGraphURI: process.env.PUBLIC_GRAPH_URI,
 	}),
-	resolve({ browser: true }),
+	resolve({
+		browser: true,
+		// @highlight-run/client is a private package not published to npm, so
+		// listing it in package.json would break end users.
+		// Instead, we add root node_modules as a resolution path so it gets
+		// resolved as an internal module and included directly in the bundle.
+		// An alternative to the previous solution using relative paths that
+		// point outside package root described here:
+		// https://www.highlight.io/blog/publishing-private-pnpm-monorepo
+		modulePaths: ['../../node_modules'],
+		// Need to override this to add .ts and .tsx as valid resolution exts.
+		extensions: ['.mjs', '.js', '.json', '.node', '.ts', '.tsx'],
+	}),
 	webWorkerLoader({
 		targetPlatform: 'browser',
 		inline: true,

Diff for: sdk/firstload/scripts/replace-client-imports.mjs

@@ -0,0 +1,30 @@
+import readdirp from 'readdirp'
+import * as path from 'node:path'
+import * as fs from 'node:fs'
+
+const workingDirectory = path.join(process.cwd(), './dist/firstload')
+const clientDirectory = path.join(process.cwd(), './dist/client')
+
+const files = await readdirp.promise(workingDirectory, {
+	fileFilter: '**/**.d.ts',
+})
+
+const text = ` from '@highlight-run/client/`
+await Promise.all(
+	files.map(async ({ fullPath }) => {
+		const content = await fs.promises.readFile(fullPath, 'utf-8')
+
+		if (!content.includes(text)) return
+
+		return fs.promises.writeFile(
+			fullPath,
+			content.replaceAll(
+				text,
+				` from '${path.relative(
+					path.dirname(fullPath),
+					clientDirectory,
+				)}/`,
+			),
+		)
+	}),
+)

Diff for: sdk/firstload/src/index.tsx

@@ -6,17 +6,20 @@ import {
 } from './integrations/amplitude'
 import { MixpanelAPI, setupMixpanelIntegration } from './integrations/mixpanel'
 import { initializeFetchListener } from './listeners/fetch'
-import { getPreviousSessionData } from '../../client/src/utils/sessionStorage/highlightSession'
-import { FirstLoadListeners } from '../../client/src/listeners/first-load-listeners'
-import { GenerateSecureID } from '../../client/src/utils/secure-id'
-import type { Highlight, HighlightClassOptions } from '../../client/src/index'
+import { getPreviousSessionData } from '@highlight-run/client/src/utils/sessionStorage/highlightSession'
+import { FirstLoadListeners } from '@highlight-run/client/src/listeners/first-load-listeners'
+import { GenerateSecureID } from '@highlight-run/client/src/utils/secure-id'
+import type {
+	Highlight,
+	HighlightClassOptions,
+} from '@highlight-run/client/src/index'
 import type {
 	HighlightOptions,
 	HighlightPublicInterface,
 	Metadata,
 	Metric,
 	SessionDetails,
-} from '../../client/src/types/types'
+} from '@highlight-run/client/src/types/types'
 import HighlightSegmentMiddleware from './integrations/segment'
 import configureElectronHighlight from './environments/electron'
 

Diff for: sdk/firstload/src/integrations/amplitude.ts

@@ -1,6 +1,6 @@
 // @ts-nocheck
-import type { AmplitudeIntegrationOptions } from '../../../client/src/types/client'
-import type { Integration } from '../../../client/src/types/types'
+import type { AmplitudeIntegrationOptions } from '@highlight-run/client/src/types/client'
+import type { Integration } from '@highlight-run/client/src/types/types'
 
 interface Window {
 	amplitude?: AmplitudeAPI

Diff for: sdk/firstload/src/integrations/mixpanel.ts

@@ -1,6 +1,6 @@
 // @ts-nocheck
-import type { MixpanelIntegrationOptions } from '../../../client/src/types/client'
-import type { Integration } from '../../../client/src/types/types'
+import type { MixpanelIntegrationOptions } from '@highlight-run/client/src/types/client'
+import type { Integration } from '@highlight-run/client/src/types/types'
 
 interface Window {
 	mixpanel?: MixpanelAPI

Diff for: sdk/firstload/src/integrations/segment.ts

@@ -1,4 +1,4 @@
-import type { HighlightPublicInterface } from '../../../client/src/types/types'
+import type { HighlightPublicInterface } from '@highlight-run/client/src/types/types'
 
 interface SegmentContext {
 	payload: any

Diff for: sdk/firstload/src/listeners/fetch/index.ts

@@ -1,5 +1,5 @@
-import type { HighlightFetchWindow } from '../../../../client/src/listeners/network-listener/utils/fetch-listener'
-import type { HighlightPublicInterface } from '../../../../client/src/types/types'
+import type { HighlightFetchWindow } from '@highlight-run/client/src/listeners/network-listener/utils/fetch-listener'
+import type { HighlightPublicInterface } from '@highlight-run/client/src/types/types'
 
 type HighlightWindow = Window & {
 	H: HighlightPublicInterface

Diff for: yarn.lock

@@ -33832,6 +33832,7 @@ __metadata:
     "@size-limit/file": ^8.1.0
     "@types/chrome": ^0.0.144
     esbuild: ^0.14.47
+    readdirp: ^3.6.0
     rollup: ^2.79.1
     rollup-plugin-consts: ^1.1.0
     rollup-plugin-esbuild: ^4.9.1
@@ -46757,7 +46758,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"readdirp@npm:~3.6.0":
+"readdirp@npm:^3.6.0, readdirp@npm:~3.6.0":
   version: 3.6.0
   resolution: "readdirp@npm:3.6.0"
   dependencies: