Template values in yaml must be escaped

[nandenjin]

How to repro

Input value contains : as description in setup

Result

It makes this:

// docs/src/index.md
---
home: true
heroImage: https://v1.vuepress.vuejs.org/hero.png
tagline: The Moon: the only satellite of our home planet
actionText: Quick Start →
actionLink: /guide/
features:
- title: Feature 1 Title
  details: Feature 1 Description
- title: Feature 2 Title
  details: Feature 2 Description
- title: Feature 3 Title
  details: Feature 3 Description
footer: Made by Kazumi Inada with ❤️
---

yarn dev returns following error:

YAMLException: incomplete explicit mapping pair; a key node is missed; or followed by a non-tabulated empty line at line 4, column 17:
    tagline: The Moon: the only satellite of our home planet
                    ^
    at generateError (/Users/nandenjin/workspace/sample-project/node_modules/js-yaml/lib/js-yaml/loader.js:167:10)
    at throwError (/Users/nandenjin/workspace/sample-project/node_modules/js-yaml/lib/js-yaml/loader.js:173:9)
    at readBlockMapping (/Users/nandenjin/workspace/sample-project/node_modules/js-yaml/lib/js-yaml/loader.js:1027:9)
    at composeNode (/Users/nandenjin/workspace/sample-project/node_modules/js-yaml/lib/js-yaml/loader.js:1359:12)
    at readDocument (/Users/nandenjin/workspace/sample-project/node_modules/js-yaml/lib/js-yaml/loader.js:1525:3)
    at loadDocuments (/Users/nandenjin/workspace/sample-project/node_modules/js-yaml/lib/js-yaml/loader.js:1588:5)
    at load (/Users/nandenjin/workspace/sample-project/node_modules/js-yaml/lib/js-yaml/loader.js:1614:19)
    at Object.safeLoad (/Users/nandenjin/workspace/sample-project/node_modules/js-yaml/lib/js-yaml/loader.js:1637:10)
    at module.exports (/Users/nandenjin/workspace/sample-project/node_modules/gray-matter/lib/parse.js:12:17)
    at parseMatter (/Users/nandenjin/workspace/sample-project/node_modules/gray-matter/index.js:109:17)
    at Object.matter [as default] (/Users/nandenjin/workspace/sample-project/node_modules/gray-matter/index.js:50:10)
    at parseFrontmatter (/Users/nandenjin/workspace/sample-project/node_modules/@vuepress/shared-utils/lib/parseFrontmatter.js:8:33)
    at Page.process (/Users/nandenjin/workspace/sample-project/node_modules/@vuepress/core/lib/node/Page.js:106:44)
    at async App.addPage (/Users/nandenjin/workspace/sample-project/node_modules/@vuepress/core/lib/node/App.js:354:5)
    at async /Users/nandenjin/workspace/sample-project/node_modules/@vuepress/core/lib/node/App.js:339:7
    at async Promise.all (index 3)
error Command failed with exit code 1.

How to fix

Add escape step at templates contains YAML.