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postgraphile

graphql-shield as 'makeProcessSchemaPlugin' in Postgraphile


Tried postgrphile example but not sure where mistake were done?

I am trying to implement graphql-shield as a plugin

    middlewarePlugin = makeProcessSchemaPlugin((schema: typeof GraphQLSchema) => {
        return applyMiddleware(schema, permissions);
    });

permission.ts

const { rule, shield } = require("graphql-shield");

const isAuthenticated = rule()((parent: any, args: any,  user: any ) => {
    return user !== null;
});

const permissions = shield({
    Query: {
        viewer: isAuthenticated
    }
});

export = permissions;

I import middlewarePlugin as others plugins in postgraphile:

  appendPlugins: [
            myClass.myPlugin,
            myClass.jsonPlace,
            myClass.middlewarePlugin
        ],

crash log:

| A serious error occurred when building the initial schema. Exiting because retryOnInitFail is not set. Error details: graphql | graphql | TypeError: Cannot read property 'fragment' of undefined graphql | at isMiddlewareWithFragment (/home/node/app/node_modules/graphql-middleware/src/utils.ts:25:17) graphql | at Object.isMiddlewareFunction (/home/node/app/node_modules/graphql-middleware/src/utils.ts:33:10) graphql | at Object.validateMiddleware (/home/node/app/node_modules/graphql-middleware/src/validation.ts:9:7) graphql | at addMiddlewareToSchema (/home/node/app/node_modules/graphql-middleware/src/middleware.ts:33:27) graphql | at normalisedMiddlewares.reduceRight.schema.schema (/home/node/app/node_modules/graphql-middleware/src/middleware.ts:91:11) graphql | at Array.reduceRight () graphql | at applyMiddlewareWithOptions (/home/node/app/node_modules/graphql-middleware/src/middleware.ts:80:77) graphql | at applyMiddleware (/home/node/app/node_modules/graphql-middleware/src/middleware.ts:132:10) graphql | at hook (/home/node/app/resolvers/test.resolver.ts:254:16) graphql | at SchemaBuilder.applyHooks (/home/node/app/node_modules/graphile-build/src/SchemaBuilder.js:398:20)


Solution

  • The type of middleware postgraphile expects is a little different from graphql-middleware. Instead of downloading graphql-middleware and graphql-shield and trying to get them to work with postgraphile, I ended up writing my own "shield" with makeWrapResolversPlugin. Example:

    const filter = (ctx) => {
      // Only attempting to do auth for non-root things, because
      // with postgraphile, all the data gets fetched at the root
      if (ctx.scope.isRootMutation || ctx.scope.isRootQuery) {
        // return this to make it available to the wrapper function
        return ctx.scope.fieldName
      }
      // return null to not wrap this non-root resolver
      return null
    }
    
    const wrapper = (fieldName) => 
      async (resolve, source, args, context) => {
        // Unless we're doing createUser, do an auth check
    
        // 👍
        if (fieldName === "createUser") return resolve()
    
        const isAuthenticated = await getIsAuthenticated(context)
    
        // 👍
        if (isAuthenticated) return resolve()
    
        throw new Error("Unauthorized");
      }
    
    const Permissions = makeWrapResolversPlugin(filter, wrapper)