feat(comments): add global comments as exports

lib/antlr/visitors/exportVisitor.ts

@@ -1,4 +1,4 @@
-import { CharStreams, CommonTokenStream } from 'antlr4ts';
+import { CharStreams, CommonTokenStream, Token } from 'antlr4ts';
 import { ParseTreeWalker } from 'antlr4ts/tree/ParseTreeWalker';
 import { SolidityLexer } from '../generated/SolidityLexer';
 import { SolidityListener } from '../generated/SolidityListener';
@@ -12,9 +12,12 @@ import {
 } from '../generated/SolidityParser';
 import { ExportType, ExportVisitResult, VisitCallback } from './types';
 
+const HIDDEN_CHANNEL = 1;
+
 export class SolidityExportVisitor {
   #inputContent: string;
   #antlrTree: SourceUnitContext;
+  #comments: Token[] = [];
   constructor(inputContent: string) {
     this.#inputContent = inputContent;
 
@@ -23,11 +26,74 @@ export class SolidityExportVisitor {
     const tokens = new CommonTokenStream(lexer);
     const parser = new SolidityParser(tokens);
     this.#antlrTree = parser.sourceUnit();
+
+    this.#comments = tokens
+      .getRange(0, tokens.size)
+      .filter((t) => t.channel === HIDDEN_CHANNEL);
   }
 
   visit(onVisit: VisitCallback<ExportVisitResult>) {
-    const listener: SolidityListener = new ExportVisitor(onVisit);
+    const listener: SolidityListener = new ExportVisitor((visitResult) => {
+      this.onVisit(visitResult, onVisit);
+    });
     ParseTreeWalker.DEFAULT.walk(listener, this.#antlrTree);
+    this.flushComments(onVisit);
+  }
+
+  private onVisit(
+    visitResult: ExportVisitResult,
+    onVisit: VisitCallback<ExportVisitResult>,
+  ) {
+    if (!this.#comments.length) {
+      return onVisit(visitResult);
+    }
+    this.emitCommentsBefore(visitResult, onVisit);
+    onVisit(visitResult);
+  }
+
+  private emitCommentsBefore(
+    visitResult: ExportVisitResult,
+    onVisit: VisitCallback<ExportVisitResult>,
+  ) {
+    while (
+      this.#comments.length &&
+      this.#comments[0].startIndex < visitResult.start
+    ) {
+      const comment = this.#comments.shift();
+      if (!comment) {
+        continue;
+      }
+      onVisit(this.buildComment(comment));
+    }
+    while (
+      this.#comments.length &&
+      this.#comments[0].stopIndex < visitResult.end
+    ) {
+      const skipped = this.#comments.shift();
+    }
+  }
+
+  private flushComments(onVisit: VisitCallback<ExportVisitResult>) {
+    if (!this.#comments.length) {
+      return;
+    }
+
+    this.#comments.forEach((comment) => onVisit(this.buildComment(comment)));
+  }
+
+  private buildComment(comment: Token): ExportVisitResult {
+    return {
+      abstract: false,
+      body: {
+        start: comment.startIndex,
+        end: comment.stopIndex,
+      },
+      start: comment.startIndex,
+      end: comment.stopIndex,
+      is: null,
+      name: `Comment#${comment.startIndex}`,
+      type: 'comment',
+    };
   }
 }
 

lib/antlr/visitors/types.ts

@@ -14,7 +14,7 @@ export interface ImportVisitNamedImport {
   as: string | null
 }
 
-export type ExportType = 'contract' | 'library' | 'interface' | 'struct' | 'enum';
+export type ExportType = 'contract' | 'library' | 'interface' | 'struct' | 'enum' | 'comment';
 
 export interface ExportVisitResult extends RangeVisitResult {
   abstract: boolean;

lib/exportsAnalyzer.ts

@@ -5,7 +5,7 @@ import { SolidityExportVisitor } from './antlr/visitors/exportVisitor';
 const error = Debug('sol-merger:error');
 
 export interface ExportsAnalyzerResult {
-  type: 'contract' | 'library' | 'interface' | 'struct' | 'enum';
+  type: 'contract' | 'library' | 'interface' | 'struct' | 'enum' | 'comment';
   name: string;
   is: string;
   body: string;

lib/fileAnalyzer.ts

@@ -16,6 +16,10 @@ export class FileAnalyzer {
     newName: string | null,
     globalRenames: RegistredImport[],
   ): string {
+    if (e.type === 'comment') {
+      return e.body;
+    }
+
     let is = e.is;
     if (is) {
       globalRenames.forEach((i) => {

lib/merger.ts

@@ -64,7 +64,11 @@ export class Merger {
       await this.init(file);
     }
     if (this.importRegistry.isImportProcessed(parentImport?.importStatement)) {
-      debug('  %s Import statement already processed: %s', '⚠', parentImport?.importStatement);
+      debug(
+        '  %s Import statement already processed: %s',
+        '⚠',
+        parentImport?.importStatement,
+      );
       return '';
     }
     if (parentImport) {
@@ -150,6 +154,9 @@ export class Merger {
     );
 
     const shouldBeImported = (exportName: string) => {
+      if (e.type === 'comment' && (isAllImport || isRenameGlobalImport)) {
+        return true;
+      }
       return (
         isAllImport ||
         isRenameGlobalImport ||
@@ -169,7 +176,7 @@ export class Merger {
       analyzedFile.filename,
       e.name,
       rename,
-    );
+    )
     if (isImported) {
       debug('%s Already imported: %s %s', '⚠', e.name, analyzedFile.filename);
       return [];

test/compiled/ContactWithKeywordsInsideString.sol

@@ -20,6 +20,8 @@ contract ConflictingInheritance {
 
 }
 
+// This contract will not be detected
+
 contract B {
     uint private b;
 

test/compiled/GlobalComments.sol

@@ -0,0 +1,21 @@
+pragma solidity 0.6.0;
+
+
+/*
+ * Multiline Comment Before
+ */
+
+// This is not included Before
+
+contract MyContract {
+    // This is included
+    function myFunction() {
+        // This is included
+    }
+}
+
+// This is not included After
+
+/*
+ * Multiline Comment After
+ */

test/contracts/Enum.sol

@@ -1,6 +1,6 @@
 pragma solidity ^0.4.0;
 
-enum State1 { Created1, Locked1, Inactive1 } // Enum
+enum State1 { Created1, Locked1, Inactive1 }
 
 contract Purchase {
     enum State { Created, Locked, Inactive } // Enum

test/contracts/GlobalComments.sol

@@ -0,0 +1,16 @@
+pragma solidity 0.6.0;
+
+/*
+ * Multiline Comment Before
+ */
+// This is not included Before
+contract MyContract {
+    // This is included
+    function myFunction() {
+        // This is included
+    }
+}
+// This is not included After
+/*
+ * Multiline Comment After
+ */

test/exportsAnalyzer.spec.ts

@@ -68,14 +68,36 @@ describe('ExportsAnalyzer', () => {
       ]);
     });
 
-    it('should return empty array if there are no exports', () => {
+    it('should return comments array', () => {
       const exportsAnalyzer = new ExportsAnalyzer(`
         // Some contracts without exports
 
         // Some contract text that is not required here
       `);
       const exports = exportsAnalyzer.analyzeExports();
 
+      assert.deepEqual(exports, [
+        {
+          body: '// Some contracts without exports',
+          is: '',
+          name: 'Comment#9',
+          type: 'comment',
+        },
+        {
+          body: '// Some contract text that is not required here',
+          is: '',
+          name: 'Comment#52',
+          type: 'comment',
+        },
+      ]);
+    });
+
+    it('should return empty array if there are no exports', () => {
+      const exportsAnalyzer = new ExportsAnalyzer(`
+
+      `);
+      const exports = exportsAnalyzer.analyzeExports();
+
       assert.deepEqual(exports, []);
     });
   });

test/index.spec.ts

@@ -83,6 +83,10 @@ describe('Solidity Merger', () => {
     await testFile('ImportStruct');
   });
 
+  it('should compile while when importing the struct', async () => {
+    await testFile('GlobalComments');
+  });
+
   it('should compile file without imports and exports (empty content)', async () => {
     const merger = new Merger();
     const file = path.join(__dirname, `/contracts/EmptyFile.sol`);