Extract Ionicons used in Ionic4 app (use at your own risk)

add-all-icons-to-build.js

'use strict';

const fs = require('fs');
const template = require(process.cwd() + '/bin/angular-template.json');

template.projects.app.architect.build.options.assets.push({
  glob: '**/*.svg',
  input: 'node_modules/ionicons/dist/ionicons/svg',
  output: './svg',
});

fs.writeFileSync(
  process.cwd() + '/angular.json',
  JSON.stringify(template, null, 2),
);

add-found-icons-to-build.js

'use strict';

const fs = require('fs');
const template = require(process.cwd() + '/bin/angular-template.json');
const foundIcons = fs
  .readFileSync(process.cwd() + '/bin/found-icons.txt')
  .toString()
  .split('\n');

foundIcons.filter(icon => icon).map(icon => {
  template.projects.app.architect.build.options.assets.push({
    glob: icon,
    input: 'node_modules/ionicons/dist/ionicons/svg',
    output: './svg',
  });
});

fs.writeFileSync(
  process.cwd() + '/angular.json',
  JSON.stringify(template, null, 2),
);

angular-template.json

{
  "$schema": "./node_modules/@angular-devkit/core/src/workspace/workspace-schema.json",
  "version": 1,
  "defaultProject": "app",
  "newProjectRoot": "projects",
  "projects": {
    "app": {
      "root": "",
      "sourceRoot": "src",
      "projectType": "application",
      "prefix": "app",
      "schematics": {},
      "architect": {
        "build": {
          "builder": "@angular-devkit/build-angular:browser",
          "options": {
            "outputPath": "www",
            "index": "src/index.html",
            "main": "src/main.ts",
            "polyfills": "src/polyfills.ts",
            "tsConfig": "src/tsconfig.app.json",
            "assets": [{
                "glob": "**/*",
                "input": "src/assets",
                "output": "assets"
              },
              "src/manifest.json",
              "src/robots.txt",
              "src/browserconfig.xml",
              "src/favicon.ico",
              {
                "glob": "**/*-sw.js",
                "input": "src/app/sw",
                "output": "/"
              }
            ],
            "styles": [{
                "input": "src/theme/variables.scss"
              },
              {
                "input": "src/global.scss"
              }
            ],
            "scripts": []
          },
          "configurations": {
            "production": {
              "fileReplacements": [{
                "replace": "src/environments/environment.ts",
                "with": "src/environments/environment.prod.ts"
              }],
              "optimization": true,
              "outputHashing": "all",
              "sourceMap": false,
              "extractCss": true,
              "namedChunks": false,
              "aot": true,
              "extractLicenses": true,
              "vendorChunk": false,
              "buildOptimizer": true,
              "serviceWorker": true,
              "budgets": [{
                "type": "initial",
                "maximumWarning": "2mb",
                "maximumError": "5mb"
              }]
            },
            "ci": {
              "progress": false
            }
          }
        },
        "serve": {
          "builder": "@angular-devkit/build-angular:dev-server",
          "options": {
            "browserTarget": "app:build"
          },
          "configurations": {
            "production": {
              "browserTarget": "app:build:production"
            },
            "ci": {
              "progress": false
            }
          }
        },
        "extract-i18n": {
          "builder": "@angular-devkit/build-angular:extract-i18n",
          "options": {
            "browserTarget": "app:build"
          }
        },
        "test": {
          "builder": "@angular-devkit/build-angular:karma",
          "options": {
            "main": "src/test.ts",
            "polyfills": "src/polyfills.ts",
            "tsConfig": "src/tsconfig.spec.json",
            "karmaConfig": "src/karma.conf.js",
            "styles": [],
            "scripts": [],
            "assets": [{
                "glob": "favicon.ico",
                "input": "src/",
                "output": "/"
              },
              {
                "glob": "**/*",
                "input": "src/assets",
                "output": "/assets"
              },
              "src/manifest.json"
            ]
          },
          "configurations": {
            "ci": {
              "progress": false,
              "watch": false
            }
          }
        },
        "lint": {
          "builder": "@angular-devkit/build-angular:tslint",
          "options": {
            "tsConfig": ["src/tsconfig.app.json", "src/tsconfig.spec.json"],
            "exclude": ["**/node_modules/**"]
          }
        },
        "ionic-cordova-build": {
          "builder": "@ionic/angular-toolkit:cordova-build",
          "options": {
            "browserTarget": "app:build"
          },
          "configurations": {
            "production": {
              "browserTarget": "app:build:production"
            }
          }
        },
        "ionic-cordova-serve": {
          "builder": "@ionic/angular-toolkit:cordova-serve",
          "options": {
            "cordovaBuildTarget": "app:ionic-cordova-build",
            "devServerTarget": "app:serve"
          },
          "configurations": {
            "production": {
              "cordovaBuildTarget": "app:ionic-cordova-build:production",
              "devServerTarget": "app:serve:production"
            }
          }
        }
      }
    },
    "app-e2e": {
      "root": "e2e/",
      "projectType": "application",
      "architect": {
        "e2e": {
          "builder": "@angular-devkit/build-angular:protractor",
          "options": {
            "protractorConfig": "e2e/protractor.conf.js",
            "devServerTarget": "app:serve"
          },
          "configurations": {
            "ci": {
              "devServerTarget": "app:serve:ci"
            }
          }
        },
        "lint": {
          "builder": "@angular-devkit/build-angular:tslint",
          "options": {
            "tsConfig": "e2e/tsconfig.e2e.json",
            "exclude": ["**/node_modules/**"]
          }
        }
      }
    }
  },
  "cli": {
    "defaultCollection": "@ionic/angular-toolkit"
  },
  "schematics": {
    "@ionic/angular-toolkit:component": {
      "styleext": "scss"
    },
    "@ionic/angular-toolkit:page": {
      "styleext": "scss"
    }
  }
}

extract-found-icons.sh

grep -R './src/app/' -o -e 'ion-icon name=".*"' \
    | awk '{print $2}' \
    | sort \
    | uniq \
    > ./bin/found-icons.txt \
  && sed \
    -i '' \
    -e 's/^name="\(.*\)"$/\1.svg/g' \
    ./bin/found-icons.txt \
  && node ./bin/add-found-icons-to-build