Add tests for command-line parser (#102)

* Add tests for command-line parser

Previously, we didn't have any tests for how we parsed command-line
flags. This was problematic because the tests didn't catch breaking
changes in seemingly innocent pull requests like #100
that rename a variable. Now, we have tests for the command-line parser
so that we hopefully catch more unintentional regressions in the future.

* Step 1: rename infertsconfig file to fix capitalization

* Step 2: rename infertsconfig file back with correct capitalization

* Fix parsing of --cwd and address review comments

Author: olafurpg

package.json

@@ -33,7 +33,7 @@
   },
   "homepage": "https://github.com/sourcegraph/lsif-typescript#readme",
   "dependencies": {
-    "commander": "^9.1.0",
+    "commander": "^9.2.0",
     "google-protobuf": "^3.20.0",
     "pretty-ms": "^7.0.1",
     "progress": "^2.0.3",

src/CommandLineOptions.test.ts

@@ -0,0 +1,37 @@
+import { test } from 'uvu'
+import * as assert from 'uvu/assert'
+
+import { mainCommand, MultiProjectOptions } from './CommandLineOptions'
+
+function checkIndexParser(
+  args: string[],
+  expectedOptions: Partial<MultiProjectOptions>,
+  expectedProjects?: string[]
+): void {
+  test(args.join(' '), () => {
+    let isAssertionTriggered = false
+    const actualArguments = ['node', 'lsif-typescript.js', 'index', ...args]
+    mainCommand((projects, options) => {
+      assert.equal(options, { ...options, ...expectedOptions })
+      if (expectedProjects) {
+        assert.equal(projects, expectedProjects)
+      }
+      isAssertionTriggered = true
+    }).parse(actualArguments)
+    assert.ok(isAssertionTriggered)
+  })
+}
+
+// defaults
+checkIndexParser([], {
+  progressBar: true,
+  cwd: process.cwd(),
+  inferTsconfig: false,
+  output: 'dump.lsif-typed',
+  yarnWorkspaces: false,
+})
+
+checkIndexParser(['--cwd', 'qux'], { cwd: 'qux' })
+checkIndexParser(['--yarn-workspaces'], { yarnWorkspaces: true })
+checkIndexParser(['--infer-tsconfig'], { inferTsconfig: true })
+checkIndexParser(['--no-progress-bar'], { progressBar: false })

src/CommandLineOptions.ts

@@ -0,0 +1,53 @@
+import { Command } from 'commander'
+
+import packageJson from '../package.json'
+
+import * as lsif from './lsif'
+
+/** Configuration options to index a multi-project workspace. */
+export interface MultiProjectOptions {
+  inferTsconfig: boolean
+  progressBar: boolean
+  yarnWorkspaces: boolean
+  cwd: string
+  output: string
+  indexedProjects: Set<string>
+}
+
+/** Configuration options to index a single TypeScript project. */
+export interface ProjectOptions extends MultiProjectOptions {
+  projectRoot: string
+  projectDisplayName: string
+  writeIndex: (index: lsif.lib.codeintel.lsiftyped.Index) => void
+}
+
+export function mainCommand(
+  indexAction: (projects: string[], otpions: MultiProjectOptions) => void
+): Command {
+  const command = new Command()
+  command
+    .name('lsif-typescript')
+    .version(packageJson.version)
+    .description(
+      'LSIF indexer for TypeScript and JavaScript\nFor usage examples, see https://github.com/sourcegraph/lsif-typescript/blob/main/README.md'
+    )
+  command
+    .command('index')
+    .option('--cwd <path>', 'the working directory', process.cwd())
+    .option('--yarn-workspaces', 'whether to index all yarn workspaces', false)
+    .option(
+      '--infer-tsconfig',
+      "whether to infer the tsconfig.json file, if it's missing",
+      false
+    )
+    .option('--output <path>', 'path to the output file', 'dump.lsif-typed')
+    .option('--no-progress-bar', 'whether to disable the progress bar')
+    .argument('[projects...]')
+    .action((parsedProjects, parsedOptions) => {
+      indexAction(
+        parsedProjects as string[],
+        parsedOptions as MultiProjectOptions
+      )
+    })
+  return command
+}

src/ProjectIndexer.ts

@@ -5,11 +5,11 @@ import prettyMilliseconds from 'pretty-ms'
 import ProgressBar from 'progress'
 import * as ts from 'typescript'
 
+import { ProjectOptions } from './CommandLineOptions'
 import { FileIndexer } from './FileIndexer'
 import { Input } from './Input'
 import * as lsif from './lsif'
 import { LsifSymbol } from './LsifSymbol'
-import { ProjectOptions } from './main'
 import { Packages } from './Packages'
 
 export class ProjectIndexer {

src/inferTsConfig.test.ts renamed to src/inferTsconfig.test.ts

@@ -3,14 +3,14 @@ import * as process from 'process'
 
 import { test } from 'uvu'
 
-import { allowJsConfig, inferTsConfig, noJsConfig } from './inferTsConfig'
+import { allowJsConfig, inferTsconfig, noJsConfig } from './inferTsconfig'
 
 const inputDirectory = join(process.cwd(), 'snapshots', 'inferTsConfig')
 
 function checkDirectory(name: string, expected: string): void {
   test(name, () => {
     const directory = join(inputDirectory, name)
-    const obtained = inferTsConfig(directory)
+    const obtained = inferTsconfig(directory)
     if (obtained !== expected) {
       throw new Error(`expected ('${expected}') != obtained ('${obtained}')`)
     }

src/inferTsConfig.ts renamed to src/inferTsconfig.ts

@@ -2,7 +2,7 @@ import * as fs from 'fs'
 import * as path from 'path'
 
 /**
- * To limit the risk of making the `inferTsConfig` run for a very long time, we
+ * To limit the risk of making the `inferTsconfig` run for a very long time, we
  * stop the file traversal after visiting this number of files.
  */
 const maximumFileTraversalCount = 1_000
@@ -19,7 +19,7 @@ export const noJsConfig = '{}'
  * If the directory contains at least one `*.{ts,tsx}` file then the config will be empty (`{}`).
  * If the directory doesn't contains one `*.{ts,tsx}` file then the config will
  */
-export function inferTsConfig(projectPath: string): string {
+export function inferTsconfig(projectPath: string): string {
   let hasTypeScriptFile = false
   let hasJavaScriptFile = false
   let visitedFileCount = 0

src/main.ts

@@ -4,59 +4,25 @@ import * as fs from 'fs'
 import * as path from 'path'
 import * as url from 'url'
 
-import { Command } from 'commander'
 import * as ts from 'typescript'
 
 import packageJson from '../package.json'
 
-import { inferTsConfig } from './inferTsConfig'
+import {
+  mainCommand,
+  MultiProjectOptions,
+  ProjectOptions,
+} from './CommandLineOptions'
+import { inferTsconfig } from './inferTsconfig'
 import * as lsif from './lsif'
 import { ProjectIndexer } from './ProjectIndexer'
 
 export const lsiftyped = lsif.lib.codeintel.lsiftyped
 
-/** Configuration options to index a multi-project workspace. */
-export interface MultiProjectOptions {
-  inferTsconfig: boolean
-  progressBar: boolean
-  yarnWorkspaces: boolean
-  cwd: string
-  output: string
-  indexedProjects: Set<string>
-}
-
-/** Configuration options to index a single TypeScript project. */
-export interface ProjectOptions extends MultiProjectOptions {
-  projectRoot: string
-  projectDisplayName: string
-  writeIndex: (index: lsif.lib.codeintel.lsiftyped.Index) => void
-}
-
 export function main(): void {
-  const program = new Command()
-  program
-    .name('lsif-typescript')
-    .version(packageJson.version)
-    .description('LSIF indexer for TypeScript and JavaScript')
-  program
-    .command('index')
-    .option('--cwd', 'the working directory', process.cwd())
-    .option('--yarn-workspaces', 'whether to index all yarn workspaces', false)
-    .option(
-      '--infer-tsconfig',
-      "whether to infer the tsconfig.json file, if it's missing",
-      false
-    )
-    .option('--output', 'path to the output file', 'dump.lsif-typed')
-    .option('--no-progress-bar', 'whether to disable the progress bar')
-    .argument('[projects...]')
-    .action((parsedProjects, parsedOptions) => {
-      indexCommand(
-        parsedProjects as string[],
-        parsedOptions as MultiProjectOptions
-      )
-    })
-  program.parse(process.argv)
+  mainCommand((projects, options) => indexCommand(projects, options)).parse(
+    process.argv
+  )
   return
 }
 
@@ -147,7 +113,7 @@ function indexSingleProject(options: ProjectOptions): void {
     }
     if (!ts.sys.fileExists(tsconfigFileName)) {
       if (options.inferTsconfig) {
-        fs.writeFileSync(tsconfigFileName, inferTsConfig(projectPath))
+        fs.writeFileSync(tsconfigFileName, inferTsconfig(projectPath))
       } else {
         console.error(`- ${options.projectDisplayName} (missing tsconfig.json)`)
         return

yarn.lock

@@ -891,10 +891,10 @@ color-name@~1.1.4:
   resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.4.tgz#c2a09a87acbde69543de6f63fa3995c826c536a2"
   integrity sha512-dOy+3AuW3a2wNbZHIuMZpTcgjGuLU/uBL/ubcZF9OXbDo8ff4O8yVp5Bf0efS8uEoYo5q4Fx7dY9OgQGXgAsQA==
 
-commander@^9.1.0:
-  version "9.1.0"
-  resolved "https://registry.yarnpkg.com/commander/-/commander-9.1.0.tgz#a6b263b2327f2e188c6402c42623327909f2dbec"
-  integrity sha512-i0/MaqBtdbnJ4XQs4Pmyb+oFQl+q0lsAmokVUH92SlSw4fkeAcG3bVon+Qt7hmtF+u3Het6o4VgrcY3qAoEB6w==
+commander@^9.2.0:
+  version "9.2.0"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-9.2.0.tgz#6e21014b2ed90d8b7c9647230d8b7a94a4a419a9"
+  integrity sha512-e2i4wANQiSXgnrBlIatyHtP1odfUp0BbV5Y5nEGbxtIrStkEOAAzCUirvLBNXHLr7kwLvJl6V+4V3XV9x7Wd9w==
 
 comment-parser@^0.7.6:
   version "0.7.6"