Static generator for tailwind styles & colors

generate.js

@@ -0,0 +1,46 @@
+import {program} from 'commander';
+import fs from 'fs';
+import path from 'path';
+import rewiremock from 'rewiremock';
+
+program
+    .option('-c, --config <tailwind.config.js>', 'tailwind config file input')
+    .option(
+        '-o, --output <file>',
+        'generated react-native-tailwind output (default: rn-tailwind.ts)'
+    );
+
+program.parse(process.argv);
+
+const configFile = program.config || 'simpleConfig.stub.js';
+const outputFile = program.output || 'rn-tailwind.ts';
+
+const config = require(path.isAbsolute(configFile)
+    ? configFile
+    : path.join(process.cwd(), configFile));
+if (!config || !config.theme) {
+    throw new Error('Tailwind config appears to be invalid');
+}
+
+const outputPath = path.isAbsolute(outputFile)
+    ? outputFile
+    : path.join(process.cwd(), outputFile);
+if (fs.existsSync(outputPath)) {
+    throw new Error('Output file already exists - refusing to overwrite.');
+}
+
+// Override internal require in `configHandler.js` with commandline input
+rewiremock('../../../tailwind.config').with(config);
+// Mock StyleSheet.create to just return input object, to get "bare" output from `tailwind.js`
+rewiremock('react-native').with({StyleSheet: {create: o => o}});
+
+// Run tailwind and color generators
+const tailwind = rewiremock.proxy('./tailwind').default;
+const color = rewiremock.proxy('./color').default;
+
+// Hack: template together a TypeScript file for use in RN project
+const output = `
+import { StyleSheet } from 'react-native';
+export const t = StyleSheet.create(${JSON.stringify(tailwind)});
+export const color = ${JSON.stringify(color)};`;
+fs.writeFileSync(outputPath, output);

package.json

@@ -28,11 +28,14 @@
     },
     "devDependencies": {
         "@babel/core": "^7.10.5",
+        "@babel/node": "^7.10.5",
         "@babel/preset-env": "^7.10.4",
         "babel-jest": "^26.1.0",
+        "commander": "^6.0.0",
         "jest": "^26.1.0",
         "react": "^16.13.1",
         "react-native": "^0.63.2",
-        "react-test-renderer": "^16.13.1"
+        "react-test-renderer": "^16.13.1",
+        "rewiremock": "^3.14.3"
     }
 }