[android] add sign task

haxetool/android.js

@@ -1,4 +1,5 @@
 const fs = require('fs');
+const os = require('os');
 const path = require('path');
 const exec = require('./exec');
 const {StringWritable} = require('./tail');
@@ -89,12 +90,16 @@ class Android extends Sdk {
         });
     }
 
-    aapt(args) {
+    buildTool(name) {
         let buildToolsVersion = null;
         fs.readdirSync(path.join(this.path, 'build-tools')).forEach(file => {
             buildToolsVersion = file;
         });
-        const aaptBin = path.join(this.path, 'build-tools', buildToolsVersion, 'aapt');
+        return path.join(this.path, 'build-tools', buildToolsVersion, name);
+    }
+
+    aapt(args) {
+        const aaptBin = this.buildTool('aapt');
         return exec('.', [aaptBin].concat(args).join(' '));
     }
 
@@ -191,6 +196,27 @@ class Android extends Sdk {
             }));
         });
     }
+
+    sign(keystore, keypass) {
+        const self = this;
+        return through.obj(function(file, enc, callback) {
+            self.log.i('sign *%s*', file.path);
+            const filename = path.join(os.tmpdir(), 'tmp.apk');
+            fs.writeFileSync(filename, file.contents);
+            const cmd = [
+                self.buildTool('apksigner'),
+                'sign',
+                '--ks', keystore,
+                '--ks-pass', `pass:${keypass}`,
+                filename
+            ].join(' ');
+            exec('.', cmd).then(() => {
+                file.contents = fs.readFileSync(filename);
+                this.push(file);
+                callback();
+            });
+        });
+    }
 }
 
 Android.ID = 'android';