feat(cli): add info command to list available compilers

src/cli/commands/index.ts

@@ -1,3 +1,4 @@
 export * from './build';
 export * from './compile';
+export * from './info';
 export * from './migrate';

src/cli/commands/info.ts

@@ -0,0 +1,39 @@
+const compilerList = [
+    'node-sass',
+    'sass',
+    'sass-embedded'
+];
+
+export function cliInfo() {
+    const compilerInfo = getCompilerInfo(compilerList);
+
+    if (compilerInfo.length > 0) {
+        process.stdout.write('The following sass compilers are installed:\n');
+        compilerInfo.forEach(info => {
+            const [ main ] = info.split('\n');
+            const [ compiler, version ] = main.split('\t');
+
+            process.stdout.write(`- ${compiler}\t${version}\n`);
+        });
+    } else {
+        process.stdout.write('No sass compilers found!\n');
+    }
+}
+
+function getCompilerInfo(compilerList : string[]) {
+    const compilerInfo: string[] = [];
+    compilerList.forEach(name => {
+        try {
+            // eslint-disable-next-line @typescript-eslint/no-var-requires
+            const { info } = require(name);
+
+            if (info) {
+                compilerInfo.push( info );
+            }
+        } catch (e) {
+            // no compiler with such name
+        }
+    });
+
+    return compilerInfo;
+}