feat(nsis): option NSIS warnings as errors

Closes #763

src/metadata.ts

@@ -354,6 +354,15 @@ export interface NsisOptions {
    * [LCID Dec](https://msdn.microsoft.com/en-au/goglobal/bb964664.aspx), defaults to `1033`(`English - United States`).
    */
   readonly language?: string | null
+
+  /*
+  Defaults to `false`.
+
+  If `warningsAsErrors` is `true` (default): NSIS will treat warnings as errors.
+
+  If `warningsAsErrors` is `false`: NSIS will allow warnings.
+   */
+  readonly warningsAsErrors?: boolean | null
 }
 
 /*
@@ -584,4 +593,4 @@ export function archFromString(name: string): Arch {
   }
 
   throw new Error(`Unsupported arch ${name}`)
-}
+}

src/targets/nsis.ts

@@ -185,7 +185,7 @@ export default class NsisTarget extends Target {
   }
 
   private async executeMakensis(defines: any, commands: any, isInstaller: boolean, originalScript: string) {
-    const args: Array<string> = ["-WX"]
+    const args: Array<string> = (this.options.warningsAsErrors === false) ? [] : ["-WX"]
     for (let name of Object.keys(defines)) {
       const value = defines[name]
       if (value == null) {
@@ -271,4 +271,4 @@ export default class NsisTarget extends Target {
       childProcess.stdin.end(script)
     })
   }
-}
+}