Angular schematic function to remove import from file. Inspired by `insertImport` from the angular cli repo.

removeImport.ts

import { findNodes } from '@schematics/angular/utility/ast-utils';
import { NoopChange, RemoveChange } from '@schematics/angular/utility/change';
import {
  ImportSpecifier,
  isStringLiteral,
  SourceFile,
  SyntaxKind,
} from 'typescript';

/**
 * Remove symbol import. Remove entire import statement if it would be left empty
 * @param fileToEdit (file we want to remove import from)
 * @param symbolName (item to remove)
 * @param fileName (path to the file)
 * @return Change
 */
export function removeImport(
  source: SourceFile,
  fileToEdit: string,
  symbolName: string,
  fileName: string,
) {
  const rootNode = source;
  const allImports = findNodes(rootNode, SyntaxKind.ImportDeclaration);

  const relevantImports = allImports.filter((node) =>
    node
      .getChildren()
      .filter(isStringLiteral)
      .map((n) => n.text)
      .includes(fileName),
  );

  const importSpecifierNode = relevantImports
    .flatMap((n) => findNodes(n, SyntaxKind.ImportSpecifier))
    .map((n) => n as ImportSpecifier)
    .find((n) =>
      findNodes(n, SyntaxKind.Identifier)
        .map((i) => i.getText())
        .includes(symbolName),
    );

  if (!importSpecifierNode) {
    return new NoopChange();
  }

  const deleteNode =
    importSpecifierNode.parent.elements.length === 1
      ? importSpecifierNode.parent.parent.parent
      : importSpecifierNode;

  return new RemoveChange(
    fileToEdit,
    deleteNode.getStart(),
    deleteNode.getText(),
  );
}