LUMO-28: Runtime option for disabling --use_strict

CHANGELOG.md

@@ -6,6 +6,11 @@
 
 - Highlight the matching brace when inserting a closing brace.
 
+### Changes
+
+- Stop compiling Lumo with a static `--use-strict` V8 flag, allows to override it
+at runtime ([#28](https://github.com/anmonteiro/lumo/issues/28)).
+
 ## [1.0.0-alpha3](https://github.com/anmonteiro/lumo/compare/1.0.0-alpha2...1.0.0-alpha3) (2016-11-15)
 
 ### Changes
@@ -23,15 +28,15 @@ indentation.
 ### New features
 
 - Add `load` REPL special function. Same as [Clojure's `load`](http://clojure.github.io/clojure/clojure.core-api.html#clojure.core/load).
-- Add support for Windows-formatted class paths [#18](https://github.com/anmonteiro/lumo/pull/18).
+- Add support for Windows-formatted class paths ([#18](https://github.com/anmonteiro/lumo/pull/18)).
 - Add support for indentation via Parinfer when multiline editing.
 
 ### Bug fixes
 
 - Lack of OpenSSL support breaks some Node.js modules ([#2](https://github.com/anmonteiro/lumo/issues/2)).
 - Allow foreign libraries to side-effect the global scope when required.
 - Improve error message when a path is not passed to `-k` ([#14](https://github.com/anmonteiro/lumo/issues/14)).
-- Don't throw when loading empty files [#10](https://github.com/anmonteiro/lumo/issues/10).
+- Don't throw when loading empty files ([#10](https://github.com/anmonteiro/lumo/issues/10)).
 - `load-file` and init scripts shouldn't change the current namespace.
 - Don't crash if JAR not found when looking for upstream foreign libs ([#19](https://github.com/anmonteiro/lumo/issues/19)).
 

scripts/build.js

@@ -58,6 +58,7 @@ browserify({
     NODE_ENV: isDevBuild ? 'development' : 'production',
   }))
   .exclude('nexeres')
+  .exclude('v8')
   .bundle((err, buf) => {
     if (err) {
       throw err;

scripts/package.js

@@ -62,7 +62,7 @@ Promise.all(promises).then(() => {
     resourceRoot: 'target',
     flags: true, // use this for applications that need command line flags.
     jsFlags: [
-      '--use_strict',
+      // '--use_strict',
       // '--prepare_always_opt',
       // '--always_opt',
       // '--compiled_keyed_generic_loads',

src/cljs/lumo/repl.cljs

@@ -301,8 +301,8 @@
     (with-redefs [js/module js/undefined
                   js/exports js/undefined]
       (set! *loading-foreign* false)
-      (js/eval source))
-    (js/eval source)))
+      (js/LUMO_EVAL source))
+    (js/LUMO_EVAL source)))
 
 ;; =============================================================================
 ;; REPL plumbing

src/js/cli.js

@@ -6,6 +6,8 @@ import * as lumo from './lumo';
 import * as util from './util';
 import version from './version';
 
+// $FlowIssue: this module exists.
+const v8 = require('v8'); // eslint-disable-line import/no-unresolved
 const minimist = require('minimist');
 
 type ScriptsType = [string, string][];
@@ -180,6 +182,8 @@ export default function startCLI(): void {
   const opts = processOpts(getCLIOpts());
   const mainScript = opts._.length > 0;
 
+  v8.setFlagsFromString('--use_strict');
+
   if (mainScript) {
     opts.repl = false;
   }

src/js/cljs.js

@@ -12,6 +12,14 @@ const vm = require('vm');
 let newContext;
 let ClojureScriptContext;
 
+function lumoEval(source: string): mixed {
+  if (__DEV__) {
+    // $FlowFixMe: this type differs according to the env
+    return vm.runInContext(source, ClojureScriptContext);
+  }
+  return vm.runInThisContext(source);
+}
+
 if (__DEV__) {
   newContext = function newCtx(): vm$Context {
     const cljsSrc = lumo.load('main.js');
@@ -20,6 +28,7 @@ if (__DEV__) {
 
     const context = {
       module,
+      exports,
       require,
       process,
       console,
@@ -30,6 +39,7 @@ if (__DEV__) {
       LUMO_WRITE_CACHE: lumo.writeCache,
       LUMO_LOAD_UPS_DEPS_CLJS: lumo.loadUpstreamForeignLibs,
       LUMO_EXISTS: lumo.fileExists,
+      LUMO_EVAL: lumoEval,
       global: undefined,
     };
 
@@ -48,6 +58,7 @@ if (__DEV__) {
     global.LUMO_WRITE_CACHE = lumo.writeCache;
     global.LUMO_LOAD_UPS_DEPS_CLJS = lumo.loadUpstreamForeignLibs;
     global.LUMO_EXISTS = lumo.fileExists;
+    global.LUMO_EVAL = lumoEval;
 
     // $FlowExpectedError: only exists in the custom V8 startup snapshot
     initialize(); // eslint-disable-line no-undef