old_contents: #!/usr/bin/env node
  // Copyright 2018 Google LLC. All Rights Reserved.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  // =============================================================================
  
  // Run this script from the base directory (not the script directory):
  // ./scripts/tag-version.js
  
  var fs = require('fs');
  var exec = require('child_process').exec;
  
  var version = JSON.parse(fs.readFileSync('package.json', 'utf8')).version;
  var tag = `v${version}`;
  
  exec(`git tag ${tag}`, (err, stdout, stderr) => {
    console.log('\x1b[36m%s\x1b[0m', 'git tag command stdout:');
    console.log(stdout);
    console.log('\x1b[31m%s\x1b[0m', 'git tag command stderr:');
    console.log(stderr);
  
    if (err) {
      throw new Error(`Could not git tag with ${tag}: ${err.message}.`);
    }
    console.log(`Successfully tagged with ${tag}.`);
  });
  
  exec(`git push --tags`, (err, stdout, stderr) => {
    console.log('\x1b[36m%s\x1b[0m', 'git push tags command stdout:');
    console.log(stdout);
    console.log('\x1b[41m%s\x1b[0m', 'git push tags command stderr:');
    console.log(stderr);
  
    if (err) {
      throw new Error(`Could not push git tags: ${err.message}.`);
    }
    console.log(`Successfully pushed tags.`);
  });
  
new_contents: #!/usr/bin/env node
  // Copyright 2018 Google LLC. All Rights Reserved.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  // =============================================================================
  
  // Run this script from the base directory (not the script directory):
  // ./scripts/tag-version.js
  
  var fs = require('fs');
  var exec = require('child_process').exec;
  
  var version = JSON.parse(fs.readFileSync('package.json', 'utf8')).version;
  var tag = `tfjs-core v${version}`;
  
  exec(`git tag ${tag}`, (err, stdout, stderr) => {
    console.log('\x1b[36m%s\x1b[0m', 'git tag command stdout:');
    console.log(stdout);
    console.log('\x1b[31m%s\x1b[0m', 'git tag command stderr:');
    console.log(stderr);
  
    if (err) {
      throw new Error(`Could not git tag with ${tag}: ${err.message}.`);
    }
    console.log(`Successfully tagged with ${tag}.`);
  });
  
  exec(`git push --tags`, (err, stdout, stderr) => {
    console.log('\x1b[36m%s\x1b[0m', 'git push tags command stdout:');
    console.log(stdout);
    console.log('\x1b[41m%s\x1b[0m', 'git push tags command stderr:');
    console.log(stderr);
  
    if (err) {
      throw new Error(`Could not push git tags: ${err.message}.`);
    }
    console.log(`Successfully pushed tags.`);
  });
  
subject: Add a prefix to the tfjs-core tag so we can do a release. (#1824)