GraphQL项目中前端如何预生成Persisted Query

query Address($locale: String!) {
  address(locale: $locale) {
	  country
    province
    cities {
      city
      districts
    }
  }
}
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{
  "address": {
    "country": "China"
	  "province": "JiangSu"
    "cities": [{
         "city":"NanJing"
         "districts": "XiCheng"
    }]
  }
}
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query Address($locale: String!) {
  address(locale: $locale) {
	  country
  }
}
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{
  "address": {
    "country": "China"
  }
}
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// parseSchemaToJson
const { resolve, dirname } = require('path')
const { readFileSync } = require('fs')
const { parse: graphqlParse, print: graphqlPrint, Source, visit } = require('graphql')

const TYPENAME_FIELD = {
  kind: 'Field',
  name: {
    kind: 'Name',
    value: '__typename',
  },
};

function isField(selection) {
  return selection.kind === 'Field'
}

function addTypenameToDocument(doc) {
  return visit(doc, {
    SelectionSet: {
      enter(node, _key, parent) {
        // Don't add __typename to OperationDefinitions.
        if (parent && parent.kind === 'OperationDefinition') {
          return
        }
        // No changes if no selections.
        const { selections } = node
        if (!selections) {
          return
        }
        // If selections already have a __typename, or are part of an
        // introspection query, do nothing.
        const skip = selections.some((selection) => {
          return (
            isField(selection) &&
            (selection.name.value === '__typename' || selection.name.value.lastIndexOf('__', 0) === 0)
          )
        })
        if (skip) {
          return
        }
        // If this SelectionSet is @export-ed as an input variable, it should
        // not have a __typename field (see issue #4691).
        const field = parent
        if (isField(field) && field.directives && field.directives.some((d) => d.name.value === 'export')) {
          return
        }
        // Create and return a new SelectionSet with a __typename Field.
        return {
          ...node,
          selections: [...selections, TYPENAME_FIELD],
        }
      },
    },
  })
}

module.exports = function loadGql(filePath) {
  if (!filePath) return null
  try {
    const source = readFileSync(filePath, 'utf8')
    if (!source) return null
    const document = loadSource(source, filePath)

    return graphqlPrint(addTypenameToDocument(document))
  } catch (err) {
    console.log(err)
    return null
  }
}

function loadSource(source, filePath) {
  let document = graphqlParse(new Source(source, 'GraphQL/file'))
  document = extractImports(source, document, filePath)
  return document
}

function extractImports(source, document, filePath) {
  const lines = source.split(/(\r\n|\r|\n)/)

  const imports = []
  lines.forEach((line) => {
    // Find lines that match syntax with `#import "<file>"`
    if (line[0] !== '#') {
      return
    }

    const comment = line.slice(1).split(' ')
    if (comment[0] !== 'import') {
      return
    }

    const filePathMatch = comment[1] && comment[1].match(/^[\"\'](.+)[\"\']/)
    if (!filePathMatch || !filePathMatch.length) {
      throw new Error('#import statement must specify a quoted file path')
    }

    const itemPath = resolve(dirname(filePath), filePathMatch[1])
    imports.push(itemPath)
  })

  const contents = imports.map((path) => [readFileSync(path, 'utf8'), path])

  const nodes = contents.map(([content, fileContext]) => {
    return loadSource(content, fileContext)
  })

  const fragmentDefinitions = nodes.reduce((defs, node) => {
    defs.push(...node.definitions)
    return defs
  }, [])

  return visit(document, {
    enter(node, key, parent, path, ancestors) {
      if (node.kind === 'Document') {
        return {
          definitions: [...fragmentDefinitions, ...node.definitions],
          kind: 'Document',
        }
      }
      return node
    },
  })
}
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const crypto = require('crypto')
const loadGql = require('./parseSchemaToJson')
const SECRET_KEY = 'TRYITYOURSELF'

const queryStrings = loadGql('yourGraphqlFile.graphql')
const sha256Hash = crypto
  .createHmac('sha256', SECRET_KEY)
  .update(queryStrings)
  .digest('hex')
// Then send to backend
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