feat: support --env option for the runtime build

integration-tests/cli/env.test.js

@@ -0,0 +1,169 @@
+import test from 'brittle';
+import { EnvParser } from '../../src/env.js';
+
+test('EnvParser should parse single key-value pair', function (t) {
+  const parser = new EnvParser();
+  parser.parse('NODE_ENV=production');
+
+  t.alike(parser.getEnv(), {
+    NODE_ENV: 'production',
+  });
+});
+
+test('EnvParser should parse multiple comma-separated values', function (t) {
+  const parser = new EnvParser();
+  parser.parse('NODE_ENV=production,DEBUG=true,PORT=3000');
+
+  t.alike(parser.getEnv(), {
+    NODE_ENV: 'production',
+    DEBUG: 'true',
+    PORT: '3000',
+  });
+});
+
+test('EnvParser should merge multiple parse calls', function (t) {
+  const parser = new EnvParser();
+  parser.parse('NODE_ENV=production');
+  parser.parse('DEBUG=true');
+
+  t.alike(parser.getEnv(), {
+    NODE_ENV: 'production',
+    DEBUG: 'true',
+  });
+});
+
+test('EnvParser should inherit existing environment variables', function (t) {
+  const parser = new EnvParser();
+
+  // Set up some test environment variables
+  process.env.TEST_VAR1 = 'value1';
+  process.env.TEST_VAR2 = 'value2';
+
+  parser.parse('TEST_VAR1,TEST_VAR2');
+
+  t.alike(parser.getEnv(), {
+    TEST_VAR1: 'value1',
+    TEST_VAR2: 'value2',
+  });
+
+  // Cleanup
+  delete process.env.TEST_VAR1;
+  delete process.env.TEST_VAR2;
+});
+
+test('EnvParser should handle mixed inheritance and setting', function (t) {
+  const parser = new EnvParser();
+
+  process.env.TEST_VAR = 'inherited';
+
+  parser.parse('TEST_VAR,NEW_VAR=set');
+
+  t.alike(parser.getEnv(), {
+    TEST_VAR: 'inherited',
+    NEW_VAR: 'set',
+  });
+
+  // Cleanup
+  delete process.env.TEST_VAR;
+});
+
+test('EnvParser should handle values with spaces', function (t) {
+  const parser = new EnvParser();
+  parser.parse('MESSAGE=Hello World');
+
+  t.alike(parser.getEnv(), {
+    MESSAGE: 'Hello World',
+  });
+});
+
+test('EnvParser should handle values with equals signs', function (t) {
+  const parser = new EnvParser();
+  parser.parse('DATABASE_URL=postgres://user:pass@localhost:5432/db');
+
+  t.alike(parser.getEnv(), {
+    DATABASE_URL: 'postgres://user:pass@localhost:5432/db',
+  });
+});
+
+test('EnvParser should handle empty values', function (t) {
+  const parser = new EnvParser();
+  parser.parse('EMPTY=');
+
+  t.alike(parser.getEnv(), {
+    EMPTY: '',
+  });
+});
+
+test('EnvParser should handle whitespace', function (t) {
+  const parser = new EnvParser();
+  parser.parse(' KEY = value with spaces ');
+
+  t.alike(parser.getEnv(), {
+    KEY: ' value with spaces', // Leading whitespace preserved, trailing removed
+  });
+
+  // Test multiple values with whitespace
+  parser.parse(' KEY2 = value2 , KEY3 = value3 ');
+
+  t.alike(parser.getEnv(), {
+    KEY: ' value with spaces',
+    KEY2: ' value2',
+    KEY3: ' value3',
+  });
+});
+
+test('EnvParser should merge and override values', function (t) {
+  const parser = new EnvParser();
+  parser.parse('KEY=first');
+  parser.parse('KEY=second');
+
+  t.alike(parser.getEnv(), {
+    KEY: 'second',
+  });
+});
+
+test('EnvParser should throw on missing equal sign', function (t) {
+  const parser = new EnvParser();
+
+  t.exception(
+    () => parser.parse('INVALID_FORMAT'),
+    'Invalid environment variable format: INVALID_FORMAT\nMust be in format KEY=VALUE',
+  );
+});
+
+test('EnvParser should throw on empty key', function (t) {
+  const parser = new EnvParser();
+
+  t.exception(
+    () => parser.parse('=value'),
+    'Invalid environment variable format: =value\nMust be in format KEY=VALUE',
+  );
+});
+
+test('EnvParser should handle empty constructor', function (t) {
+  const parser = new EnvParser();
+
+  t.alike(parser.getEnv(), {});
+});
+
+test('EnvParser should handle multiple commas and whitespace', function (t) {
+  const parser = new EnvParser();
+  parser.parse('KEY1=value1,  KEY2=value2,,,KEY3=value3');
+
+  t.alike(parser.getEnv(), {
+    KEY1: 'value1',
+    KEY2: 'value2',
+    KEY3: 'value3',
+  });
+});
+
+test('EnvParser should handle values containing escaped characters', function (t) {
+  const parser = new EnvParser();
+
+  // This is how Node.js argv will receive it after shell processing
+  parser.parse('A=VERBATIM CONTENTS\\, GO HERE'); // Users will type: --env 'A=VERBATIM CONTENTS\, GO HERE'
+
+  t.alike(parser.getEnv(), {
+    A: 'VERBATIM CONTENTS, GO HERE', // Comma should be unescaped in final value
+  });
+});

integration-tests/js-compute/fixtures/app/fastly.toml.in

@@ -9,7 +9,7 @@ name = "js-test-app"
 service_id = ""
 
 [scripts]
-  build = "node ../../../../js-compute-runtime-cli.js --enable-experimental-high-resolution-time-methods src/index.js"
+  build = "node ../../../../js-compute-runtime-cli.js --env LOCAL_TEST,TEST=\"foo\" --enable-experimental-high-resolution-time-methods src/index.js"
 
 [local_server]
 

integration-tests/js-compute/fixtures/app/src/env.js

@@ -1,14 +1,28 @@
 /* eslint-env serviceworker */
 import { env } from 'fastly:env';
 import { routes, isRunningLocally } from './routes.js';
-import { assert } from './assertions.js';
+import { strictEqual } from './assertions.js';
+
+// hostname didn't exist at initialization, so can still be captured at runtime
+const wizerHostname = env('FASTLY_HOSTNAME');
+const wizerLocal = env('LOCAL_TEST');
 
 routes.set('/env', () => {
+  strictEqual(wizerHostname, undefined);
+
   if (isRunningLocally()) {
-    assert(
+    strictEqual(
       env('FASTLY_HOSTNAME'),
       'localhost',
       `env("FASTLY_HOSTNAME") === "localhost"`,
     );
+  } else {
+    strictEqual(env('FASTLY_HOSTNAME'), undefined);
   }
+
+  strictEqual(wizerLocal, 'local val');
+
+  // at runtime these remain captured from Wizer time, even if we didn't call env
+  strictEqual(env('LOCAL_TEST'), 'local val');
+  strictEqual(env('TEST'), 'foo');
 });

integration-tests/js-compute/test.js

@@ -11,6 +11,9 @@ import { copyFile, readFile, writeFile } from 'node:fs/promises';
 import core from '@actions/core';
 import TOML from '@iarna/toml';
 
+// test environment variable handling
+process.env.LOCAL_TEST = 'local val';
+
 async function killPortProcess(port) {
   zx.verbose = false;
   const pids = (await zx`lsof -ti:${port}`).stdout;

js-compute-runtime-cli.js

@@ -16,6 +16,7 @@ const {
   output,
   version,
   help,
+  env,
 } = await parseInputs(process.argv.slice(2));
 
 if (version) {
@@ -41,6 +42,7 @@ if (version) {
     aotCache,
     moduleMode,
     bundle,
+    env,
   );
   await addSdkMetadataField(output, enableAOT);
 }

runtime/fastly/builtins/fastly.cpp

@@ -22,12 +22,17 @@ using fastly::fetch::RequestOrResponse;
 using fastly::fetch::Response;
 using fastly::logger::Logger;
 
+extern char **environ;
+
 namespace {
 
 bool DEBUG_LOGGING_ENABLED = false;
 
 api::Engine *ENGINE;
 
+// Global storage for Wizer-time environment
+std::unordered_map<std::string, std::string> initialized_env;
+
 static void oom_callback(JSContext *cx, void *data) {
   fprintf(stderr, "Critical Error: out of memory\n");
   fflush(stderr);
@@ -319,15 +324,42 @@ bool Env::env_get(JSContext *cx, unsigned argc, JS::Value *vp) {
   if (!args.requireAtLeast(cx, "fastly.env.get", 1))
     return false;
 
-  auto var_name_chars = core::encode(cx, args[0]);
-  if (!var_name_chars) {
+  JS::RootedString str(cx, JS::ToString(cx, args[0]));
+  if (!str) {
     return false;
   }
-  JS::RootedString env_var(cx, JS_NewStringCopyZ(cx, getenv(var_name_chars.begin())));
-  if (!env_var)
+
+  JS::UniqueChars ptr = JS_EncodeStringToUTF8(cx, str);
+  if (!ptr) {
     return false;
+  }
+
+  // This shouldn't fail, since the encode operation ensured `str` is linear.
+  JSLinearString *linear = JS_EnsureLinearString(cx, str);
+  uint32_t len = JS::GetDeflatedUTF8StringLength(linear);
+
+  std::string key_str(ptr.get(), len);
+
+  // First check initialized environment
+  if (auto it = initialized_env.find(key_str); it != initialized_env.end()) {
+    JS::RootedString env_var(cx, JS_NewStringCopyN(cx, it->second.data(), it->second.size()));
+    if (!env_var)
+      return false;
+    args.rval().setString(env_var);
+    return true;
+  }
 
-  args.rval().setString(env_var);
+  // Fallback to getenv with caching
+  if (const char *value = std::getenv(key_str.c_str())) {
+    auto [it, _] = initialized_env.emplace(key_str, value);
+    JS::RootedString env_var(cx, JS_NewStringCopyN(cx, it->second.data(), it->second.size()));
+    if (!env_var)
+      return false;
+    args.rval().setString(env_var);
+    return true;
+  }
+
+  args.rval().setUndefined();
   return true;
 }
 
@@ -475,6 +507,19 @@ bool install(api::Engine *engine) {
   }
 
   // fastly:env
+  // first, store the initialized environment vars from Wizer
+  initialized_env.clear();
+
+  for (char **env = environ; *env; env++) {
+    const char *entry = *env;
+    const char *eq = entry;
+    while (*eq && *eq != '=')
+      eq++;
+
+    if (*eq == '=') {
+      initialized_env.emplace(std::string(entry, eq - entry), std::string(eq + 1));
+    }
+  }
   RootedValue env_get(engine->cx());
   if (!JS_GetProperty(engine->cx(), Fastly::env, "get", &env_get)) {
     return false;