Support for constant and variable link params

Fixed #85

Signed-off-by: Alan Cha <[email protected]>

Author: Alan-Cha

packages/oasgraph/lib/resolver_builder.js

@@ -89,34 +89,37 @@ export function getResolver ({
 
     // handle arguments provided by links
     for (let paramName in argsFromLink) {
-      let value = argsFromLink[paramName]
-
-      // parameter names can specify location of parameter (e.g., path.id)
       let paramNameWithoutLocation = paramName
       if (paramName.indexOf('.') !== -1) {
         paramNameWithoutLocation = paramName.split('.')[1]
       }
 
-      // CASE: parameter in body
-      if (/body#/.test(value)) {
-        let tokens = JSONPath.JSONPath({ path: value.split('body#/')[1], json: root })
-        if (Array.isArray(tokens) && tokens.length > 0) {
-          args[paramNameWithoutLocation] = tokens[0]
+      // link parameter
+      let value = argsFromLink[paramName]
+
+      /**
+       * see if the link parameter contains constants that are appended to the link parameter
+       * 
+       * e.g. instead of:
+       * $response.body#/employerId
+       * 
+       * it could be:
+       * abc_{$response.body#/employerId}
+       */
+      if (value.search(/{|}/) === -1) {
+        if (isRuntimeExpression(value)) {
+          args[paramNameWithoutLocation] = resolveLinkParameter(paramName, value, _oasgraph, root)
         } else {
-          log(`Warning: could not extract parameter ${paramName} form link`)
+          args[paramNameWithoutLocation] = value
         }
-        // CASE: parameter in previous query parameter
-      } else if (/query\./.test(value)) {
-        args[paramNameWithoutLocation] =
-          _oasgraph.usedParams[Oas3Tools.beautify(value.split('query.')[1])]
-        // CASE: parameter in previous path parameter
-      } else if (/path\./.test(value)) {
-        args[paramNameWithoutLocation] =
-          _oasgraph.usedParams[Oas3Tools.beautify(value.split('path.')[1])]
-        // CASE: link OASGraph currently does not support
       } else {
-        log(`Warning: could not process link parameter ${paramName} with ` +
-          `value ${value}`)
+        // replace link parameters with appropriate values
+        let linkParams = value.match(/{([^}]*)}/g)
+        linkParams.forEach((linkParam) => {
+          value = value.replace(linkParam, resolveLinkParameter(paramName, linkParam.substring(1, linkParam.length - 1), _oasgraph, root))
+        })
+
+        args[paramNameWithoutLocation] = value
       }
     }
 
@@ -428,3 +431,61 @@ function getAuthReqAndProtcolName (
     authRequired
   }
 }
+
+/**
+ * Given a link parameter, determine the value
+ * 
+ * The link parameter is a reference to data contained in the 
+ * url/method/statuscode or response/request body/query/path/header
+ */
+function resolveLinkParameter(paramName: string, value: string, _oasgraph: any, root: any): any {
+  // CASE: parameter in body
+  if (/body#/.test(value)) {
+    let tokens = JSONPath.JSONPath({ path: value.split('body#/')[1], json: root })
+    if (Array.isArray(tokens) && tokens.length > 0) {
+      return tokens[0]
+    } else {
+      log(`Warning: could not extract parameter ${paramName} from link`)
+    }
+    
+    // CASE: parameter in previous query parameter
+  } else if (/query\./.test(value)) {
+    return _oasgraph.usedParams[Oas3Tools.beautify(value.split('query.')[1])]
+
+    // CASE: parameter in previous path parameter
+  } else if (/path\./.test(value)) {
+    return _oasgraph.usedParams[Oas3Tools.beautify(value.split('path.')[1])]
+    
+    // CASE: link OASGraph currently does not support
+  } else {
+    log(`Warning: could not process link parameter ${paramName} with ` +
+      `value ${value}`)
+  }
+}
+
+/**
+ * Check if a string is a runtime expression in the context of link parameters
+ */
+function isRuntimeExpression(str: string): boolean {
+  let references = ["header.", "query.", "path.", "body"]
+
+  if (str.startsWith("$url") || str.startsWith("$method") || str.startsWith("$statusCode")) {
+    return true
+
+  } else if (str.startsWith("$request.")) {
+    for (let i = 0; i < references.length; i++) {
+      if (str.startsWith(`$request.${references[i]}`)) {
+        return true
+      }
+    }
+
+  } else if (str.startsWith("$response.")) {
+    for (let i = 0; i < references.length; i++) {
+      if (str.startsWith(`$response.${references[i]}`)) {
+        return true
+      }
+    }
+  }
+  
+  return false
+}

packages/oasgraph/lib/resolver_builder.js.map

@@ -163,6 +163,41 @@ test('Get nested resource via link operationRef', () => {
   })
 })
 
+test('Link parameters as constant and as a variable', () => {
+  let query = `{
+    scanner(query: "hello") {
+      query
+      basicQueryProtocol{
+        query
+      }
+      variableQueryProtocol{
+        query
+      }
+      constantQueryProtocol{
+        query
+      }
+    }
+  }`
+  return graphql(createdSchema, query).then(result => {
+    expect(result).toEqual({
+      data: {
+        "scanner": {
+          "query": "hello",
+          "basicQueryProtocol": {
+            "query": "hello"
+          },
+          "variableQueryProtocol": {
+            "query": "_hello_hellohelloabchello123"
+          },
+          "constantQueryProtocol": {
+            "query": "123"
+          }
+        }
+      }
+    })
+  })
+})
+
 test('Get response without providing parameter with default value', () => {
   let query = `{
     productsReviews (id: "100") {

packages/oasgraph/src/resolver_builder.ts

@@ -312,6 +312,11 @@ function startServer (PORT) {
     }
   })
 
+  app.get('/api/copier', (req, res) => {
+    console.log(req.method, req.path, req.query, req.headers)
+    res.status(200).send(req.query)
+  })
+
   app.get('/api/cleanDesks', (req, res) => {
     console.log(req.method, req.path)
     res.send('5 clean desks')
@@ -446,6 +451,11 @@ function startServer (PORT) {
     }
   })
 
+  app.get('/api/scanner', (req, res) => {
+    console.log(req.method, req.path, req.query, req.headers)
+    res.status(200).send(req.query)
+  })
+
   app.get('/api/snack', (req, res) => {
     console.log(req.method, req.path, req.query, req.headers)
     if ('snack_type' in req.headers && 'snack_size' in req.headers) {

packages/oasgraph/test/example_api.test.js

@@ -10,11 +10,11 @@ const graphqlHTTP = require('express-graphql')
 const app = express()
 const OasGraph = require('../lib/index.js')
 
-// let oas = require('./fixtures/example_oas.json')
+let oas = require('./fixtures/example_oas.json')
 // let oas = require('./fixtures/github_oas.json')
 // let oas = require('./fixtures/instagram.json')
 // let oas = require('./fixtures/government_social_work_api.json')
-let oas = require('./fixtures/weather_underground_api.json')
+// let oas = require('./fixtures/weather_underground_api.json')
 
 // const yamljs = require('yamljs')
 // const fs = require('fs')