Cannot invoke an expression whose type lacks a call signature, using moment

Question

I am trying to get moment to work in my angular application. Here is a clean sample repo to demonstrate the issue. Clone that repo and run ng build test-library in the root directory. Install packages first, npm install.

When i try to use moment, i am getting the following error. What am i doing wrong? I have been trying to fix this for a while now. I have googled it many times and tried several suggestions to no avail.

Usage:

import * as moment from 'moment';

...

  public doSomething(): string {
    const aMoment: moment.Moment = moment(); // line 22
    return aMoment.format();
  }

---

Error:

projects/test-library/src/lib/test-library.component.ts(22,36): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type 'typeof moment' has no compatible call signatures.

---

tsconfig.json

{
  "extends": "../../tsconfig.json",
  "compilerOptions": {
    "allowSyntheticDefaultImports": true,
    "esModuleInterop": true,
    "outDir": "../../out-tsc/lib",
    "target": "es2015",
    "module": "es2015",
    "moduleResolution": "node",
    "declaration": true,
    "sourceMap": true,
    "inlineSources": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "importHelpers": true,
    "types": [],
    "lib": [
      "dom",
      "es2018"
    ]
  },
  "angularCompilerOptions": {
    "annotateForClosureCompiler": true,
    "skipTemplateCodegen": true,
    "strictMetadataEmit": true,
    "fullTemplateTypeCheck": true,
    "strictInjectionParameters": true,
    "enableResourceInlining": true
  },
  "exclude": [
    "src/test.ts",
    "**/*.spec.ts"
  ]
}

Answer 1

I had the same problem. And I solved the issue in two ways.

1)I set the value of esModuleInterop false under compilerOptions

"esModuleInterop": false

2. The second way I changed the code

import * as _moment from 'moment';

to the following code

import _moment from "moment";

both options worked fine for my code.