Typescript: Why doesn't visual studio code report the same errors that the command line tsc does?

Question

If I intentionally make a typo in my code I will get an error. Here is the correct code:

declare const State: TwineState;

If I delete the last character and then type tsc on the command line, it gives me this error:

tsc/prod.spec.ts:7:22 - error TS2304: Cannot find name 'TwineStat'.

7 declare const State: TwineStat;

But Visual Studio Code doesn't seem to realize there's any error.

How I get my editor to show me the same errors that the tsc command recognizes? I'm pretty new to all these technologies so I don't know what information would be helpful to troubleshoot, but here are my config files:

package.json:

{
...
  "version": "1.0.0",
  "main": ".webpack/main",
  "scripts": {
    "compile-typescript": "tsc && cp tscbuild/prod.js story/",
    "lint": "eslint tsc/** --fix",
    "test": "npm run lint && ts-node node_modules/jasmine/bin/jasmine && npm run compile-typescript ..."
  },
  "keywords": [],
...
  "devDependencies": {
    "@types/jasmine": "^3.5.9",
    "@types/node": "^13.9.1",
    "@typescript-eslint/eslint-plugin": "^2.24.0",
    "@typescript-eslint/parser": "^2.24.0",
    "eslint": "^6.8.0",
    "eslint-plugin-testcafe": "^0.2.1",
    "jasmine": "^3.5.0",
    "testcafe": "^1.8.2",
    "ts-node": "^8.6.2",
    "typescript": "^3.7.0"
  },
  "dependencies": {}
}

tsconfig.json:

{
  "compilerOptions": {
    /* Basic Options */
    // "incremental": true,                   /* Enable incremental compilation */
    "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */
    "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
    "lib": ["es6","dom"],                           /* Specify library files to be included in the compilation. */
    "allowJs": false,                         /* Allow javascript files to be compiled. */
    // "checkJs": true,                       /* Report errors in .js files. */
    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
    // "declaration": true,                   /* Generates corresponding '.d.ts' file. */
    // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
    // "outFile": "./",                       /* Concatenate and emit output to single file. */
    "outDir": "tscbuild",                        /* Redirect output structure to the directory. */
    "rootDir": "tsc",                         /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
    // "composite": true,                     /* Enable project compilation */
    // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
    // "removeComments": true,                /* Do not emit comments to output. */
    // "noEmit": true,                        /* Do not emit outputs. */
    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */

    /* Strict Type-Checking Options */
    "strict": true,                           /* Enable all strict type-checking options. */
    "noImplicitAny": true,                    /* Raise error on expressions and declarations with an implied 'any' type. */
    "strictNullChecks": true,              /* Enable strict null checks. */
    "strictFunctionTypes": true,           /* Enable strict checking of function types. */
    "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
    "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
    "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */

    /* Additional Checks */
    "noUnusedLocals": true,                /* Report errors on unused locals. */
    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
    "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
    "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */

    /* Module Resolution Options */
    // "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
    // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
    // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
    // "typeRoots": [],                       /* List of folders to include type definitions from. */
    // "types": [],                           /* Type declaration files to be included in compilation. */
    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
    "esModuleInterop": true,                  /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
    // "allowUmdGlobalAccess": true,          /* Allow accessing UMD globals from modules. */

    /* Source Map Options */
    // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
    // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */

    /* Experimental Options */
    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */

    /* Advanced Options */
    "resolveJsonModule": true,                /* Include modules imported with '.json' extension */
    "forceConsistentCasingInFileNames": true  /* Disallow inconsistently-cased references to the same file. */
  }
}

.eslintrc.js:

module.exports = {
  env: {
    browser: true,
    es6: true,
    node: true,
    jasmine: true,
  },
  "extends": [
    "eslint:recommended",
    "plugin:@typescript-eslint/recommended",
    "plugin:testcafe/recommended"
  ],
  globals: {
    Atomics: "readonly",
    SharedArrayBuffer: "readonly"
  },
  parser: "@typescript-eslint/parser",
  parserOptions: {
    ecmaVersion: 2018,
    project: "./tsconfig.json",
  },
  plugins: ["@typescript-eslint", "testcafe"],
  rules: {
    quotes: ["error", "double"],
    "no-plusplus": ["off"],
    "@typescript-eslint/camelcase": ["off"]
  }
};

Answer 1

There are probably a number of reasons that this happens. This sometimes happens to me and I can't explain why this happens but I have noticed that the incremental feature/flag in tsconfig.json can cause the transpiler to cache outdated data which would cause these differences. It appears that VSCode might not use the incremental cached data and the command line does.

There are two ways to test and fix this. One is the flip the flag for incremental in the tsconfig.json to false. When I've done this the errors will appear on the command line. Problem is that when you flip it back to true those errors then disappear. The other option is delete your outDir - often called dist/ or build/ or something similar.

A third option that I haven't confirmed is to delete the tsconfig.tsbuildinfo file only which is usually in the outDir as well. There's a setting in tsconfig.json called tsBuildInfoFile that will redirect this file to whatever value you specify for that prop so if you can't find it in the outDir try that location.