feat(cli): add support for export plugins in cli

bin/pluginsLoader.ts

@@ -0,0 +1,73 @@
+import Debug from 'debug';
+import path from 'path';
+import { ExportPluginCtor, ExportPluginModule } from '../lib/types';
+import { Utils } from '../lib/utils';
+
+const info = Debug('sol-merger:info');
+const error = Debug('sol-merger:error');
+
+export class PluginLoadError extends Error {
+  constructor(message: string) {
+    super(message);
+  }
+}
+
+export class PluginsLoader {
+  #pluginPaths: string[];
+  #npmRoot: string;
+
+  constructor(pluginPaths: string[], npmRoot: string) {
+    this.#pluginPaths = pluginPaths;
+    this.#npmRoot = npmRoot;
+  }
+
+  async getPlugins(): Promise<ExportPluginCtor[]> {
+    const result: ExportPluginCtor[] = [];
+    for (const pluginPath of this.#pluginPaths) {
+      const fullPluginPath = this.getPluginPath(pluginPath);
+      if (!fullPluginPath) {
+        continue;
+      }
+      try {
+        const plugin = await this.tryLoadPlugin(fullPluginPath);
+        result.push(plugin);
+      } catch (e) {
+        if (e instanceof Error) {
+          error(e.message);
+        } else {
+          error(e);
+        }
+      }
+    }
+    return result;
+  }
+
+  private getPluginPath(pluginPath: string): string | null {
+    if (!this.#npmRoot && !Utils.isRelative(pluginPath)) {
+      info(
+        `[PluginsLoader] SKIP: Unable to load plugin '${pluginPath}' because npmRoot is not found.`,
+      );
+      return null;
+    }
+
+    if (Utils.isRelative(pluginPath)) {
+      return path.join(process.cwd(), pluginPath);
+    }
+    return path.join(this.#npmRoot, pluginPath);
+  }
+
+  private async tryLoadPlugin(modulePath: string): Promise<ExportPluginCtor> {
+    const resolvedPath = path.resolve(modulePath);
+    const pluginModule: Partial<ExportPluginModule> = await import(
+      resolvedPath
+    ).catch((e) => {
+      throw new PluginLoadError(`Can not import plugin ${resolvedPath}`);
+    });
+    if (pluginModule.ExportPlugin) {
+      return pluginModule.ExportPlugin;
+    }
+    throw new PluginLoadError(
+      `Plugin ${resolvedPath} does not have exported member ExportPlugin`,
+    );
+  }
+}

bin/sol-merger.ts

@@ -1,13 +1,16 @@
 #!/usr/bin/env node
 
-import fs from 'fs-extra';
-import path from 'path';
-import glob from 'glob';
 import colors from 'cli-color';
+import program from 'commander';
 import Debug from 'debug';
+import fs from 'fs-extra';
+import glob from 'glob';
+import path from 'path';
 import { Merger } from '../lib/merger';
+import { ExportPluginCtor } from '../lib/types';
+import { Utils } from '../lib/utils';
 import { done } from '../utils/done';
-import program from 'commander';
+import { PluginsLoader } from './pluginsLoader';
 
 const debug = Debug('sol-merger:debug');
 
@@ -18,6 +21,12 @@ let append = '';
 program
   .option('-a, --append [append]', '', /^([a-zA-Z_]+)$/)
   .option('-c, --remove-comments', `Remove comment from exports`, false)
+  .option(
+    '-p, --export-plugin [pathToPlugin]',
+    `Add post processor for exports`,
+    collectExportPluginOption,
+    [],
+  )
   .arguments('<glob> [outputDir]')
   .action((_glob, _outputDir) => {
     inputGlob = _glob;
@@ -41,6 +50,7 @@ if (outputDir) {
 
 debug('Output directory', outputDir);
 debug('RemoveComments?', program.removeComments);
+debug('ExportPlugins?', program.exportPlugin);
 
 glob(
   inputGlob,
@@ -59,14 +69,16 @@ async function execute(err: Error, files: string[]) {
   debug(files);
 
   if (files.length === 0) {
-    // eslint-disable-next-line
     console.log(colors.yellow('No files found for merge'));
   }
 
+  const exportPlugins = await getExportPlugins(program.exportPlugin);
+
   const promises = files.map(async (file) => {
     const merger = new Merger({
       delimeter: '\n\n',
       removeComments: program.removeComments,
+      exportPlugins,
     });
     let result: string;
     result = await merger.processFile(file, true);
@@ -88,3 +100,15 @@ async function execute(err: Error, files: string[]) {
     .then(() => done())
     .catch(done);
 }
+
+function collectExportPluginOption(value: string, previousValue: string[]) {
+  return previousValue.concat([value]);
+}
+
+async function getExportPlugins(
+  plugins: string[],
+): Promise<ExportPluginCtor[]> {
+  const npmRoot = await Utils.getNodeModulesPath(process.cwd());
+  const loader = new PluginsLoader(plugins, npmRoot);
+  return loader.getPlugins();
+}

lib/merger.ts

@@ -226,17 +226,7 @@ export class Merger {
   }
 
   async getNodeModulesPath(file: string): Promise<string> {
-    return new Promise((resolve, reject) => {
-      exec('npm root', { cwd: path.dirname(file) }, (err, stdout) => {
-        if (err) {
-          error(
-            'Unable to find npm root directory. Make sure contract is inside npm package.',
-          );
-          return reject(err);
-        }
-        resolve(stdout.trim());
-      });
-    });
+    return Utils.getNodeModulesPath(file);
   }
 
   private isComment(str: string) {

lib/types.ts

@@ -17,3 +17,7 @@ export interface ExportPluginProcessor {
 export type ExportPluginCtor<
   T extends ExportPluginProcessor = ExportPluginProcessor
 > = new () => T;
+
+export interface ExportPluginModule {
+  ExportPlugin: ExportPluginCtor
+}

lib/utils.ts

@@ -1,5 +1,25 @@
+import { exec } from 'child_process';
+import Debug from 'debug';
+import path from 'path';
+
+const error = Debug('sol-merger:error');
+
 export class Utils {
   static isRelative(file: string) {
     return file.startsWith('.');
   }
+
+  static async getNodeModulesPath(file: string): Promise<string> {
+    return new Promise((resolve, reject) => {
+      exec('npm root', { cwd: path.dirname(file) }, (err, stdout) => {
+        if (err) {
+          error(
+            'Unable to find npm root directory. Make sure contract is inside npm package.',
+          );
+          return reject(err);
+        }
+        resolve(stdout.trim());
+      });
+    });
+  }
 }