refactor: made adding a new loader easier

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

src/loaders/env.ts

@@ -0,0 +1,65 @@
+import type { Environment } from '../types.js'
+
+/**
+ * Parse out all env vars from a given env file string and return an object
+ */
+export function parseEnvString(envFileString: string): Environment {
+  // First thing we do is stripe out all comments
+  envFileString = stripComments(envFileString.toString())
+
+  // Next we stripe out all the empty lines
+  envFileString = stripEmptyLines(envFileString)
+
+  // Merge the file env vars with the current process env vars (the file vars overwrite process vars)
+  return parseEnvVars(envFileString)
+}
+
+/**
+ * Parse out all env vars from an env file string
+ */
+export function parseEnvVars(envString: string): Environment {
+  const envParseRegex = /^((.+?)[=](.*))$/gim
+  const matches: Environment = {}
+  let match
+  while ((match = envParseRegex.exec(envString)) !== null) {
+    // Note: match[1] is the full env=var line
+    const key = match[2].trim()
+    let value: string | number | boolean = match[3].trim()
+
+    // remove any surrounding quotes
+    value = value
+      .replace(/(^['"]|['"]$)/g, '')
+      .replace(/\\n/g, '\n')
+
+    // Convert string to JS type if appropriate
+    if (value !== '' && !isNaN(+value)) {
+      matches[key] = +value
+    }
+    else if (value === 'true') {
+      matches[key] = true
+    }
+    else if (value === 'false') {
+      matches[key] = false
+    }
+    else {
+      matches[key] = value
+    }
+  }
+  return JSON.parse(JSON.stringify(matches)) as Environment
+}
+
+/**
+ * Strips out comments from env file string
+ */
+export function stripComments(envString: string): string {
+  const commentsRegex = /(^\s*#.*$)/gim
+  return envString.replace(commentsRegex, '')
+}
+
+/**
+ * Strips out newlines from env file string
+ */
+export function stripEmptyLines(envString: string): string {
+  const emptyLinesRegex = /(^\n)/gim
+  return envString.replace(emptyLinesRegex, '')
+}

src/parse-env-file.ts

@@ -3,6 +3,7 @@ import { extname } from 'node:path'
 import { pathToFileURL } from 'node:url'
 import { resolveEnvFilePath, IMPORT_HOOK_EXTENSIONS, isPromise } from './utils.js'
 import type { Environment } from './types.ts'
+import { parseEnvString } from './loaders/env.js';
 
 /**
  * Gets the environment vars from an env file
@@ -34,74 +35,13 @@ export async function getEnvFileVars(envFilePath: string): Promise<Environment>
     if (isPromise(env)) {
       env = await env
     }
+    return env;
   }
-  else {
-    const file = readFileSync(absolutePath, { encoding: 'utf8' })
-    env = parseEnvString(file)
-  }
-  return env
-}
-
-/**
- * Parse out all env vars from a given env file string and return an object
- */
-export function parseEnvString(envFileString: string): Environment {
-  // First thing we do is stripe out all comments
-  envFileString = stripComments(envFileString.toString())
-
-  // Next we stripe out all the empty lines
-  envFileString = stripEmptyLines(envFileString)
 
-  // Merge the file env vars with the current process env vars (the file vars overwrite process vars)
-  return parseEnvVars(envFileString)
-}
-
-/**
- * Parse out all env vars from an env file string
- */
-export function parseEnvVars(envString: string): Environment {
-  const envParseRegex = /^((.+?)[=](.*))$/gim
-  const matches: Environment = {}
-  let match
-  while ((match = envParseRegex.exec(envString)) !== null) {
-    // Note: match[1] is the full env=var line
-    const key = match[2].trim()
-    let value: string | number | boolean = match[3].trim()
-
-    // remove any surrounding quotes
-    value = value
-      .replace(/(^['"]|['"]$)/g, '')
-      .replace(/\\n/g, '\n')
+  const file = readFileSync(absolutePath, { encoding: 'utf8' })
 
-    // Convert string to JS type if appropriate
-    if (value !== '' && !isNaN(+value)) {
-      matches[key] = +value
-    }
-    else if (value === 'true') {
-      matches[key] = true
-    }
-    else if (value === 'false') {
-      matches[key] = false
-    }
-    else {
-      matches[key] = value
-    }
+  switch (ext) {
+    default:
+      return parseEnvString(file)
   }
-  return JSON.parse(JSON.stringify(matches)) as Environment
-}
-
-/**
- * Strips out comments from env file string
- */
-export function stripComments(envString: string): string {
-  const commentsRegex = /(^\s*#.*$)/gim
-  return envString.replace(commentsRegex, '')
-}
-
-/**
- * Strips out newlines from env file string
- */
-export function stripEmptyLines(envString: string): string {
-  const emptyLinesRegex = /(^\n)/gim
-  return envString.replace(emptyLinesRegex, '')
 }

test/loaders/env.spec.ts

@@ -0,0 +1,136 @@
+import { assert } from 'chai'
+import {
+  stripEmptyLines,
+  stripComments,
+  parseEnvVars,
+  parseEnvString,
+} from '../../src/loaders/env.js'
+
+describe('stripEmptyLines', (): void => {
+  it('should strip out all empty lines', (): void => {
+    const envString = stripEmptyLines(
+      '\nBOB=COOL\n\nNODE_ENV=dev\n\nANSWER=42 AND COUNTING\n\n',
+    )
+    assert(envString === 'BOB=COOL\nNODE_ENV=dev\nANSWER=42 AND COUNTING\n')
+  })
+})
+
+describe('stripComments', (): void => {
+  it('should strip out all full line comments', (): void => {
+    const envString = stripComments(
+      '#BOB=COOL\nNODE_ENV=dev\nANSWER=42 AND COUNTING\n#AnotherComment\n',
+    )
+    assert(envString === '\nNODE_ENV=dev\nANSWER=42 AND COUNTING\n\n')
+  })
+
+  it('should not strip out #s from values', (): void => {
+    const envString = stripComments(
+      '#\nBOB=COMMENT#ELL\n#\nNODE_ENV=dev\nANSWER=42 AND COUNTING\n#AnotherComment\n',
+    )
+    assert(
+      envString ===
+        '\nBOB=COMMENT#ELL\n\nNODE_ENV=dev\nANSWER=42 AND COUNTING\n\n',
+      envString,
+    )
+  })
+})
+
+describe('parseEnvVars', (): void => {
+  it("should parse out all env vars in string when not ending with '\\n'", (): void => {
+    const envVars = parseEnvVars(
+      'BOB=COOL\nNODE_ENV=dev\nANSWER=42 AND COUNTING\nNUMBER=42\nBOOLEAN=true',
+    )
+    assert(envVars.BOB === 'COOL')
+    assert(envVars.NODE_ENV === 'dev')
+    assert(envVars.ANSWER === '42 AND COUNTING')
+    assert(envVars.NUMBER === 42)
+    assert(envVars.BOOLEAN === true)
+  })
+
+  it("should parse out all env vars in string with format 'key=value'", (): void => {
+    const envVars = parseEnvVars(
+      'BOB=COOL\nNODE_ENV=dev\nANSWER=42 AND COUNTING\n',
+    )
+    assert(envVars.BOB === 'COOL')
+    assert(envVars.NODE_ENV === 'dev')
+    assert(envVars.ANSWER === '42 AND COUNTING')
+  })
+
+  it('should ignore invalid lines', (): void => {
+    const envVars = parseEnvVars(
+      'BOB=COOL\nTHISIS$ANDINVALIDLINE\nANSWER=42 AND COUNTING\n',
+    )
+    assert(Object.keys(envVars).length === 2)
+    assert(envVars.BOB === 'COOL')
+    assert(envVars.ANSWER === '42 AND COUNTING')
+  })
+
+  it('should default an empty value to an empty string', (): void => {
+    const envVars = parseEnvVars('EMPTY=\n')
+    assert(envVars.EMPTY === '')
+  })
+
+  it('should escape double quoted values', (): void => {
+    const envVars = parseEnvVars('DOUBLE_QUOTES="double_quotes"\n')
+    assert(envVars.DOUBLE_QUOTES === 'double_quotes')
+  })
+
+  it('should escape single quoted values', (): void => {
+    const envVars = parseEnvVars("SINGLE_QUOTES='single_quotes'\n")
+    assert(envVars.SINGLE_QUOTES === 'single_quotes')
+  })
+
+  it('should preserve embedded double quotes', (): void => {
+    const envVars = parseEnvVars(
+      'DOUBLE=""""\nDOUBLE_ONE=\'"double_one"\'\nDOUBLE_TWO=""double_two""\n',
+    )
+    assert(envVars.DOUBLE === '""')
+    assert(envVars.DOUBLE_ONE === '"double_one"')
+    assert(envVars.DOUBLE_TWO === '"double_two"')
+  })
+
+  it('should preserve newlines when surrounded in quotes', (): void => {
+    const envVars = parseEnvVars(
+      'ONE_NEWLINE="ONE\\n"\nTWO_NEWLINES="HELLO\\nWORLD\\n"\nTHREE_NEWLINES="HELLO\\n\\nWOR\\nLD"\n',
+    )
+    assert(envVars.ONE_NEWLINE === 'ONE\n')
+    assert(envVars.TWO_NEWLINES === 'HELLO\nWORLD\n')
+    assert(envVars.THREE_NEWLINES === 'HELLO\n\nWOR\nLD')
+  })
+
+  it('should preserve embedded single quotes', (): void => {
+    const envVars = parseEnvVars(
+      "SINGLE=''''\nSINGLE_ONE=''single_one''\nSINGLE_TWO=\"'single_two'\"\n",
+    )
+    assert(envVars.SINGLE === "''")
+    assert(envVars.SINGLE_ONE === "'single_one'")
+    assert(envVars.SINGLE_TWO === "'single_two'")
+  })
+
+  it('should parse out all env vars ignoring spaces around = sign', (): void => {
+    const envVars = parseEnvVars(
+      'BOB = COOL\nNODE_ENV =dev\nANSWER= 42 AND COUNTING',
+    )
+    assert(envVars.BOB === 'COOL')
+    assert(envVars.NODE_ENV === 'dev')
+    assert(envVars.ANSWER === '42 AND COUNTING')
+  })
+
+  it('should parse out all env vars ignoring spaces around = sign', (): void => {
+    const envVars = parseEnvVars(
+      'BOB = "COOL "\nNODE_ENV = dev\nANSWER= \' 42 AND COUNTING\'',
+    )
+    assert(envVars.BOB === 'COOL ')
+    assert(envVars.NODE_ENV === 'dev')
+    assert(envVars.ANSWER === ' 42 AND COUNTING')
+  })
+})
+
+describe('parseEnvString', (): void => {
+  it('should parse env vars and merge (overwrite) with process.env vars', (): void => {
+    const env = parseEnvString('BOB=COOL\nNODE_ENV=dev\nANSWER=42\n')
+    assert(env.BOB === 'COOL')
+    assert(env.NODE_ENV === 'dev')
+    assert(env.ANSWER === 42)
+  })
+})