Do not cache file contents in memory, version bump

Author: Li0liQ

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Master
 
+## 0.4.7 - Decrease memory consumption
+
+- Do not cache file contents in memory for faster ast parsing; this will significantly decrease memory requirements for larger codebases
+
 ## 0.4.6 - Faster dependency resolution
 
 - Bump dependencies

package.json

@@ -1,6 +1,6 @@
 {
     "name": "stricter",
-    "version": "0.4.6",
+    "version": "0.4.7",
     "description": "A project-wide js-linting tool",
     "files": [
         "LICENSE",

src/file-processor/index.ts

@@ -38,7 +38,8 @@ const readFileData = (
     logger: Logger,
 ): FileData => {
     const source = readFile(filePath);
-    const ast = parsedExtensionsRe.test(filePath) ? () => parse(source, filePath) : undefined;
+    const isParsedExtension = parsedExtensionsRe.test(filePath);
+    const getAst = isParsedExtension ? () => parse(filePath) : undefined;
     let dependencies: string[] | undefined;
 
     const hash = getHash(source);
@@ -47,10 +48,10 @@ const readFileData = (
     if (cachedValue && cachedValue.hash === hash) {
         dependencies = cachedValue.dependencies;
     } else {
-        if (ast) {
+        if (isParsedExtension) {
             let parsedAst: any;
             try {
-                parsedAst = ast();
+                parsedAst = parse(filePath, source);
             } catch (e) {
                 logger.error(`Unable to parse ${filePath}`);
                 throw e;
@@ -62,7 +63,7 @@ const readFileData = (
 
     const result = {
         source,
-        ast,
+        ast: getAst,
         dependencies,
     };
 

src/file-processor/parse-imports.test.ts

@@ -5,10 +5,10 @@ describe('resolveImport', () => {
     it('should count require', () => {
         const result = parseImports(
             parse(
+                'filePath',
                 `
             const test1 = require('test-file1');
         `,
-                'filePath',
             ),
         );
 
@@ -19,10 +19,10 @@ describe('resolveImport', () => {
     it('should count es6 dynamic import', () => {
         const result = parseImports(
             parse(
+                'filePath',
                 `
             const test1 = import('test-file1');
         `,
-                'filePath',
             ),
         );
 
@@ -33,13 +33,13 @@ describe('resolveImport', () => {
     it('should count es6 imports', () => {
         const result = parseImports(
             parse(
+                'filePath',
                 `
             import { default as test1 } from 'test-file1';
             import { test2, test3 } from 'test-file2';
             import test4 from 'test-file3';
             import * as test5 from 'test-file4';
         `,
-                'filePath',
             ),
         );
 
@@ -55,12 +55,12 @@ describe('resolveImport', () => {
     it('should count es6 reexports', () => {
         const result = parseImports(
             parse(
+                'filePath',
                 `
             export { default as test1 } from 'test-file1';
             export { test2, test3 } from 'test-file2';
             export * from 'test-file3';
         `,
-                'filePath',
             ),
         );
 
@@ -71,11 +71,11 @@ describe('resolveImport', () => {
     it('should not count exports', () => {
         const result = parseImports(
             parse(
+                'filePath',
                 `
             export default () => {};
             export const test = () => {};
         `,
-                'filePath',
             ),
         );
 
@@ -86,11 +86,11 @@ describe('resolveImport', () => {
     it('should ignore dynamic imports', () => {
         const result = parseImports(
             parse(
+                'filePath',
                 `
             const test1 = require(foo);
             const test2 = import(foo);
         `,
-                'filePath',
             ),
         );
 
@@ -101,10 +101,10 @@ describe('resolveImport', () => {
     it('should count TS import equals declaration', () => {
         const result = parseImports(
             parse(
+                'filePath.tsx',
                 `
             import test1 = require('test-file1');
         `,
-                'filePath.tsx',
             ),
         );
 
@@ -115,10 +115,10 @@ describe('resolveImport', () => {
     it('should count jest.requireActual', () => {
         const result = parseImports(
             parse(
+                'filePath',
                 `
             const test1 = jest.requireActual('test-file1');
         `,
-                'filePath',
             ),
         );
 

src/utils/index.ts

@@ -97,7 +97,11 @@ const defaultPlugins: parser.ParserPlugin[] = [
     'throwExpressions',
 ] as parser.ParserPlugin[];
 
-export const parse = (source: string, filePath: string): any => {
+export const parse = (filePath: string, source?: string): any => {
+    if (!source) {
+        source = readFile(filePath);
+    }
+
     const plugins = [...defaultPlugins];
     const fileType = /\.([jt])s(x?)$/.exec(filePath);
 

src/utils/test.ts

@@ -4,6 +4,10 @@ jest.mock('fs');
 jest.mock('path');
 jest.mock('@babel/parser');
 
+afterEach(() => {
+    jest.resetAllMocks();
+});
+
 describe('readFile', () => {
     it('reads file in utf8', () => {
         const fileName = 'test';
@@ -161,7 +165,28 @@ describe('parse', () => {
         parseMock.mockImplementation((i: string) => i);
 
         const src = 'test';
-        const result = parse(src, 'filePath');
+        const result = parse('filePath', src);
+
+        expect(parseMock.mock.calls.length).toBe(1);
+        expect(parseMock.mock.calls[0][0]).toBe(src);
+        expect(result).toBe(src);
+    });
+
+    it('reads file if not provided', () => {
+        const src = 'test';
+        const fileName = 'filePath';
+
+        const { parse: parseMock } = require('@babel/parser');
+        parseMock.mockImplementation((i: string) => i);
+
+        const { readFileSync } = require('fs');
+        readFileSync.mockReturnValueOnce(src);
+
+        const result = parse(fileName);
+
+        expect(readFileSync.mock.calls.length).toBe(1);
+        expect(readFileSync.mock.calls[0][0]).toBe(fileName);
+        expect(readFileSync.mock.calls[0][1]).toBe('utf8');
 
         expect(parseMock.mock.calls.length).toBe(1);
         expect(parseMock.mock.calls[0][0]).toBe(src);