android: use script to call npm and node on macOS

On macOS, if Android Studio is not started through the command line,
the PATH environment variable will probably not contain the location
of node and npm due to macOS environment variables in Windowed
Applications not being the same. This commit adds code to create a
helper script that calls npm after adding the PATH elements that are
available during the plugin's install, so that npm and node can
be called when the Gradle build is started by Android Studio.

android/build.gradle

@@ -123,10 +123,58 @@ if (shouldRebuildNativeModules==null) {
 }
 
 if ("1".equals(shouldRebuildNativeModules)) {
+
+    String npmCommandName = 'npm';
+    String nodeCommandName = 'node';
+    if (OperatingSystem.current().isMacOsX()) {
+        // On macOS, npm's and node's locations may not be in the PATH environment variable if gradle is being run
+        // by Android Studio. We need npm to build native modules and node to run node-pre-gyp patches, so we use
+        // helper scripts that are created when the plugin is installed to run npm and node with the PATH members that
+        // were available during the plugin's install.
+        try {
+            def commandResult = exec {
+                commandLine 'command', '-v', 'npm'
+                ignoreExitValue = true
+            }
+            if ( commandResult.getExitValue() != 0 ) {
+                // If npm is not found by command, use the helper script.
+                logger.warn("Couldn't find npm in the PATH for building native modules. Will try to use a helper script.");
+                npmCommandName = '../build-native-modules-MacOS-helper-script-npm.sh';
+            }
+            commandResult = exec {
+                commandLine 'command', '-v', 'node'
+                ignoreExitValue = true
+            }
+            if ( commandResult.getExitValue() != 0 ) {
+                // If node is not found by command, use the helper script.
+                logger.warn("Couldn't find node in the PATH for building native modules. Will try to use a helper script.");
+                nodeCommandName = '../build-native-modules-MacOS-helper-script-node.sh';
+            }
+        } catch ( Exception e ) {
+            throw new GradleException('Something went wrong looking for npm and node by running "command".', e)
+        }
+    }
+
     task ApplyPatchScriptToModules (type:Exec) {
         dependsOn "CopyNodeProjectAssetsFolder"
         description "Apply patches to modules to improve compatibility."
-        commandLine 'node', "${project.projectDir}/../scripts/patch-package.js", "${rootProject.buildDir}/nodejs-assets/nodejs-project/node_modules/"
+        doFirst {
+            if (OperatingSystem.current().isMacOsX()) {
+                // Copy the helper script for calling node when building in Android Studio on macOS.
+                copy {
+                    from "${rootProject.projectDir}/../nodejs-assets/build-native-modules-MacOS-helper-script-node.sh"
+                    into "${rootProject.buildDir}/nodejs-assets/"
+                }
+            }
+        }
+        workingDir "${rootProject.buildDir}/nodejs-assets/nodejs-project/"
+        commandLine nodeCommandName, "${project.projectDir}/../scripts/patch-package.js", "${rootProject.buildDir}/nodejs-assets/nodejs-project/node_modules/"
+        doLast {
+            if (OperatingSystem.current().isMacOsX()) {
+                // Deletes the helper script so it doesn't get included in the APK.
+                delete "${rootProject.buildDir}/nodejs-assets/build-native-modules-MacOS-helper-script-node.sh"
+            }
+        }
     }
     GenerateNodeProjectAssetsLists.dependsOn "ApplyPatchScriptToModules"
 
@@ -199,8 +247,7 @@ if ("1".equals(shouldRebuildNativeModules)) {
             throw new GradleException("Unsupported opperating system for nodejs-mobile native builds: ${OperatingSystem.current().getName()}")
         }
 
-
-        task "CopyNodeProjectAssets${abi_name}"{
+        task "CopyNodeProjectAssets${abi_name}" {
             description = "Copying node assets and apply patches to build native modules for ${abi_name}."
             inputs.files fileTree (
                 dir: "${rootProject.projectDir}/../nodejs-assets/nodejs-project/"
@@ -217,8 +264,20 @@ if ("1".equals(shouldRebuildNativeModules)) {
                     from "${rootProject.projectDir}/../nodejs-assets/nodejs-project/"
                     into "${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/nodejs-project/"
                 }
+                if (OperatingSystem.current().isMacOsX()) {
+                    // Copy the helper scripts for calling npm and node when building in Android Studio on macOS.
+                    copy {
+                        from "${rootProject.projectDir}/../nodejs-assets/build-native-modules-MacOS-helper-script-node.sh"
+                        into "${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/"
+                    }
+                    copy {
+                        from "${rootProject.projectDir}/../nodejs-assets/build-native-modules-MacOS-helper-script-npm.sh"
+                        into "${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/"
+                    }
+                }
                 exec {
-                    commandLine 'node', "${project.projectDir}/../scripts/patch-package.js", "${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/nodejs-project/node_modules/"
+                    workingDir "${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/nodejs-project/"
+                    commandLine nodeCommandName, "${project.projectDir}/../scripts/patch-package.js", "${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/nodejs-project/node_modules/"
                 }
                 new File("${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/copy.timestamp").text = "${new Date().format('yyyy-MM-dd HH:mm:ss')}"
             }
@@ -238,8 +297,7 @@ if ("1".equals(shouldRebuildNativeModules)) {
             inputs.file "${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/copy.timestamp"
             outputs.file "${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/nodejs-project/"
             workingDir "${rootProject.buildDir}/nodejs-native-assets-temp-build/nodejs-native-assets-${abi_name}/nodejs-project/"
-            commandLine 'npm', '--verbose', 'rebuild', '--build-from-source'
-            //environment ('PATH', "${npm_toolchain_add_to_path}" + System.getProperty("path.separator") + "${System.env.PATH}")
+            commandLine npmCommandName, '--verbose', 'rebuild', '--build-from-source'
             environment ('npm_config_node_engine', 'v8' )
             environment ('npm_config_nodedir', "${project.projectDir}/libnode/" )
             environment ('npm_config_node_gyp', "${project.projectDir}/../../nodejs-mobile-gyp/bin/node-gyp.js" )

scripts/create-node-structure.js

@@ -73,6 +73,26 @@ function installFiles(done) {
 
   ncp(source, target, options, done);
 
+  if (process.platform === 'darwin') {
+    // Adds a helper scripts to run "npm rebuild" and "node" with the current PATH.
+    // This workaround is needed for Android Studio on macOS when it is not started
+    // from the command line, as npm and node probably won't be in the PATH at build time.
+    var helperMacOSBuildScriptPath = path.join(target, 'build-native-modules-MacOS-helper-script-npm.sh');
+    fs.writeFileSync( helperMacOSBuildScriptPath,`#!/bin/bash
+      # Helper script for Gradle to call npm on macOS in case it is not found
+      export PATH=$PATH:${process.env.PATH}
+      npm $@
+    `, {"mode": 0o755}
+    );
+    helperMacOSBuildScriptPath = path.join(target, 'build-native-modules-MacOS-helper-script-node.sh');
+    fs.writeFileSync( helperMacOSBuildScriptPath,`#!/bin/bash
+      # Helper script for Gradle to call node on macOS in case it is not found
+      export PATH=$PATH:${process.env.PATH}
+      node $@
+    `, {"mode": 0o755}
+    );
+  }
+
 }
 
 installFiles( function(err) {