Handle JSON with Comment (#39)

* chore: install strip-json-comment

* feat: strip json comment

* chore: install valibot

* feat: use valibot parsing

* feat: copy stripJsonComments

---------

Co-authored-by: farreldarian <[email protected]>

packages/generator/package.json

@@ -23,7 +23,8 @@
 		"@prisma/sdk": "4.0.0",
 		"fp-ts": "^2.16.2",
 		"lodash": "^4.17.21",
-		"pluralize": "^8.0.0"
+		"pluralize": "^8.0.0",
+		"valibot": "^0.30.0"
 	},
 	"devDependencies": {
 		"@types/lodash": "^4.14.202",

packages/generator/src/lib/strip-json-comments.ts

@@ -0,0 +1,136 @@
+// @ts-nocheck
+
+/**
+ * From https://github.com/sindresorhus/strip-json-comments/commit/f9a628340cf4134500352122cf42ab40b9de6734
+ */
+
+const singleComment = Symbol('singleComment')
+const multiComment = Symbol('multiComment')
+
+const stripWithoutWhitespace = () => ''
+const stripWithWhitespace = (string, start, end) =>
+	string.slice(start, end).replace(/\S/g, ' ')
+
+const isEscaped = (jsonString, quotePosition) => {
+	let index = quotePosition - 1
+	let backslashCount = 0
+
+	while (jsonString[index] === '\\') {
+		index -= 1
+		backslashCount += 1
+	}
+
+	return Boolean(backslashCount % 2)
+}
+
+export default function stripJsonComments(
+	jsonString,
+	{ whitespace = true, trailingCommas = false } = {}
+) {
+	if (typeof jsonString !== 'string') {
+		throw new TypeError(
+			`Expected argument \`jsonString\` to be a \`string\`, got \`${typeof jsonString}\``
+		)
+	}
+
+	const strip = whitespace ? stripWithWhitespace : stripWithoutWhitespace
+
+	let isInsideString = false
+	let isInsideComment = false
+	let offset = 0
+	let buffer = ''
+	let result = ''
+	let commaIndex = -1
+
+	for (let index = 0; index < jsonString.length; index++) {
+		const currentCharacter = jsonString[index]
+		const nextCharacter = jsonString[index + 1]
+
+		if (!isInsideComment && currentCharacter === '"') {
+			// Enter or exit string
+			const escaped = isEscaped(jsonString, index)
+			if (!escaped) {
+				isInsideString = !isInsideString
+			}
+		}
+
+		if (isInsideString) {
+			continue
+		}
+
+		if (!isInsideComment && currentCharacter + nextCharacter === '//') {
+			// Enter single-line comment
+			buffer += jsonString.slice(offset, index)
+			offset = index
+			isInsideComment = singleComment
+			index++
+		} else if (
+			isInsideComment === singleComment &&
+			currentCharacter + nextCharacter === '\r\n'
+		) {
+			// Exit single-line comment via \r\n
+			index++
+			isInsideComment = false
+			buffer += strip(jsonString, offset, index)
+			offset = index
+			continue
+		} else if (isInsideComment === singleComment && currentCharacter === '\n') {
+			// Exit single-line comment via \n
+			isInsideComment = false
+			buffer += strip(jsonString, offset, index)
+			offset = index
+		} else if (!isInsideComment && currentCharacter + nextCharacter === '/*') {
+			// Enter multiline comment
+			buffer += jsonString.slice(offset, index)
+			offset = index
+			isInsideComment = multiComment
+			index++
+			continue
+		} else if (
+			isInsideComment === multiComment &&
+			currentCharacter + nextCharacter === '*/'
+		) {
+			// Exit multiline comment
+			index++
+			isInsideComment = false
+			buffer += strip(jsonString, offset, index + 1)
+			offset = index + 1
+			continue
+		} else if (trailingCommas && !isInsideComment) {
+			if (commaIndex !== -1) {
+				if (currentCharacter === '}' || currentCharacter === ']') {
+					// Strip trailing comma
+					buffer += jsonString.slice(offset, index)
+					result += strip(buffer, 0, 1) + buffer.slice(1)
+					buffer = ''
+					offset = index
+					commaIndex = -1
+				} else if (
+					currentCharacter !== ' ' &&
+					currentCharacter !== '\t' &&
+					currentCharacter !== '\r' &&
+					currentCharacter !== '\n'
+				) {
+					// Hit non-whitespace following a comma; comma is not trailing
+					buffer += jsonString.slice(offset, index)
+					offset = index
+					commaIndex = -1
+				}
+			} else if (currentCharacter === ',') {
+				// Flush buffer prior to this point, and save new comma index
+				result += buffer + jsonString.slice(offset, index)
+				buffer = ''
+				offset = index
+				commaIndex = index
+			}
+		}
+	}
+
+	return (
+		result +
+		buffer +
+		(isInsideComment
+			? strip(jsonString.slice(offset))
+			: jsonString.slice(offset))
+	)
+}

packages/generator/src/shared/generator-context.ts

@@ -1,7 +1,9 @@
 import fs from 'node:fs'
 import path from 'node:path'
 import type { GeneratorOptions } from '@prisma/generator-helper'
+import { object, safeParse, string } from 'valibot'
 import { getModuleResolution } from '~/lib/config'
+import stripJsonComments from '~/lib/strip-json-comments'
 
 type GeneratorContext = {
 	moduleResolution?: string
@@ -30,8 +32,20 @@ function resolveModuleResolution(options: GeneratorOptions) {
 	const tsConfigPath = findTsConfig()
 	if (!tsConfigPath) return
 
-	const tsConfig = JSON.parse(fs.readFileSync(tsConfigPath, 'utf-8'))
-	return tsConfig?.compilerOptions?.moduleResolution
+	const parsing = safeParse(TsConfig, readTsConfig(tsConfigPath))
+	if (!parsing.success) return
+
+	return parsing.output.compilerOptions.moduleResolution
+}
+
+const TsConfig = object({
+	compilerOptions: object({
+		moduleResolution: string(),
+	}),
+})
+
+function readTsConfig(tsConfigPath: string) {
+	return JSON.parse(stripJsonComments(fs.readFileSync(tsConfigPath, 'utf-8')))
 }
 
 function findTsConfig() {