fix subtle bug in recursion in getDependencyGraph

apps/remix-ide/src/app/plugins/contractFlattener.tsx

@@ -1,3 +1,4 @@
+/* eslint-disable prefer-const */
 import React from 'react'
 import { Plugin } from '@remixproject/engine'
 import { customAction } from '@remixproject/plugin-api'
@@ -57,11 +58,12 @@ export class ContractFlattener extends Plugin {
     let sorted
     let result
     let sources
+    let order: string[] = []
     try {
-      dependencyGraph = getDependencyGraph(ast, filePath, input.settings.remappings)
+      dependencyGraph = getDependencyGraph(ast, filePath, input.settings.remappings, order)
       sorted = dependencyGraph.isEmpty() ? [filePath] : dependencyGraph.sort().reverse()
       sources = source.sources
-      result = concatSourceFiles(sorted, sources)
+      result = concatSourceFiles(sorted, sources, order)
     } catch (err) {
       console.warn(err)
     }

libs/remix-ui/solidity-compiler/src/lib/logic/flattenerUtilities.ts

@@ -4,39 +4,49 @@ const IMPORT_SOLIDITY_REGEX = /^\s*import(\s+).*$/gm;
 const SPDX_SOLIDITY_REGEX = /^\s*\/\/ SPDX-License-Identifier:.*$/gm;
 
 type Visited = { [key: string]: number }
-export function getDependencyGraph(ast: { [name: string]: CompilationSource }, target: string, remappings: string[]) {
+export function getDependencyGraph(ast: { [name: string]: CompilationSource }, target: string, remappings: string[], order: string[]) {
   const graph = tsort();
   const visited = {};
   visited[target] = 1;
-  _traverse(graph, visited, ast, target, remappings);
+  _traverse(graph, visited, ast, target, remappings, order);
   return graph;
 }
 
-export function concatSourceFiles(files: any[], sources: any) {
-  let concat = '';
+export function concatSourceFiles(files: any[], sources: any, order: string[]) {
+  let concat = ''
+  order.reverse().forEach((importName) => {
     for (const file of files) {
-    const source = sources[file].content;
-    const sourceWithoutImport = source.replace(IMPORT_SOLIDITY_REGEX, '');
-    const sourceWithoutSPDX = sourceWithoutImport.replace(SPDX_SOLIDITY_REGEX, '');
-    concat += `\n// File: ${file}\n\n`;
-    concat += sourceWithoutSPDX;
+      if (file === importName) {
+        const source = sources[file].content
+        const sourceWithoutImport = source.replace(IMPORT_SOLIDITY_REGEX, '')
+        const sourceWithoutSPDX = sourceWithoutImport.replace(SPDX_SOLIDITY_REGEX, '')
+        concat += `\n// File: ${file}\n\n`
+        concat += sourceWithoutSPDX
       }
-  return concat;
+      const source = sources[importName].content
+      const sourceWithoutImport = source.replace(IMPORT_SOLIDITY_REGEX, '')
+      const sourceWithoutSPDX = sourceWithoutImport.replace(SPDX_SOLIDITY_REGEX, '')
+      concat += `\n// File: ${importName}\n\n`
+      concat += sourceWithoutSPDX
+    }
+  })
+  return concat
 }
 
-function _traverse(graph: Graph, visited: Visited, ast: { [name: string]: CompilationSource }, name: string, remappings: string[]) {
+function _traverse(graph: Graph, visited: Visited, ast: { [name: string]: CompilationSource }, name: string, remappings: string[], order: string[]) {
   let currentAst = null
   currentAst = ast[name].ast
   const dependencies = _getDependencies(currentAst);
   for (const dependency of dependencies) {
     const path = resolve(name, dependency, remappings);
     if (path in visited) {
-      // continue; // fixes wrong ordering of source in flattened file
+      continue; // fixes wrong ordering of source in flattened file
     }
     visited[path] = 1;
     graph.add(name, path);
-    _traverse(graph, visited, ast, path, remappings);
+    _traverse(graph, visited, ast, path, remappings, order);
   }
+  order.push(name)
 }
 
 function _getDependencies(ast: AstNode) {