Add a watch option

Similar to the way psc-ide support works, the purs-loader now tolerates
compiler errors when the `watch` option is true. When webpack is being
run in watch mode the user can set `watch` to true in order to avoid
failing the webpack bundle creation when the PureScript compiler fails.

Resolves issue #66

Resolves issue #73

Resolves issue #74

2 files changed, 7 insertions, 1 deletions

diff --git a/src/Psc.js b/src/Psc.js
index 4991d5f..ffa32b7 100644
--- a/src/Psc.js
+++ b/src/Psc.js
@@ -45,7 +45,12 @@ function compile(psModule) {
         if (errorMessage.length) {
           psModule.emitError(errorMessage);
         }
-        reject(new Error('compilation failed'))
+        if (options.watch) {
+          resolve(psModule);
+        }
+        else {
+          reject(new Error('compilation failed'))
+        }
       } else {
         const warningMessage = stderr.join('');
         if (options.warnings && warningMessage.length) {
diff --git a/src/index.js b/src/index.js
index 3f5e6a8..f4a6dff 100644
--- a/src/index.js
+++ b/src/index.js
@@ -46,6 +46,7 @@ module.exports = function purescriptLoader(source, map) {
     bundleNamespace: 'PS',
     bundle: false,
     warnings: true,
+    watch: false,
     output: 'output',
     src: [
       path.join('src', '**', '*.purs'),