handle npx elm compile error messages

src/cli/src/cli/build.ts

@@ -137,8 +137,23 @@ const compileMainElm = (env : Environment) => async () => {
       .catch(colorElmError)
   }
 
+  const red = colors.RED
+  const green = colors.green
+
   const colorElmError = (err : string) => {
-    const errors = JSON.parse(err).errors as Error[] || []
+    let errors = []
+
+    try {
+      errors = JSON.parse(err).errors as Error[] || []
+    } catch (e) {
+      return Promise.reject([
+        `${red}Something went wrong with elm-spa.${reset}`,
+        `Please report this entire error to ${green}https://github.com/ryannhg/elm-spa/issues${reset}`,
+        `-----`,
+        err,
+        `-----`
+      ].join('\n\n'))
+    }
 
     const strIf = (str : string) => (cond : boolean) : string => cond ? str : ''
     const boldIf = strIf(bold)

src/cli/src/process.ts

@@ -2,5 +2,8 @@ import { exec } from 'child_process'
 
 export const run = (cmd : string) : Promise<unknown> =>
   new Promise((resolve, reject) =>
-    exec(cmd, (err, stdout, stderr) => err ? reject(stderr) : resolve(stdout))
+    exec(cmd, (err, stdout, stderr) => err
+      ? reject(stderr.split('npm ERR!')[0] || stderr)
+      : resolve(stdout)
+    )
   )