Merge pull request #1251 from danielpeintner/issue-1250

refactor: handle also enhanced contentTypes

Author: relu91

package-lock.json

@@ -15,6 +15,7 @@
     "main": "dist/core.js",
     "types": "dist/core.d.ts",
     "devDependencies": {
+        "@types/content-type": "^1.1.8",
         "@types/debug": "^4.1.7",
         "@types/uritemplate": "^0.3.4",
         "@types/uuid": "^8.3.1"
@@ -24,6 +25,7 @@
         "@petamoriken/float16": "^3.1.1",
         "ajv": "^8.11.0",
         "cbor": "^8.1.0",
+        "content-type": "^1.0.5",
         "debug": "^4.3.4",
         "uritemplate": "0.3.4",
         "uuid": "^7.0.3",

packages/core/package.json

@@ -21,6 +21,8 @@ import Servient from "./servient";
 import Helpers from "./helpers";
 
 import { ProtocolClient } from "./protocol-interfaces";
+import { Content } from "./content";
+import ContentType from "content-type";
 
 import ContentManager from "./content-serdes";
 
@@ -555,7 +557,33 @@ export default class ConsumedThing extends TD.Thing implements IConsumedThing {
         form = this.handleUriVariables(tp, form, options);
 
         const content = await client.readResource(form);
-        return new InteractionOutput(content, form, tp);
+        try {
+            return this.handleInteractionOutput(content, form, tp);
+        } catch (e) {
+            const error = e instanceof Error ? e : new Error(JSON.stringify(e));
+            throw new Error(`Error while processing property for ${tp.title}. ${error.message}`);
+        }
+    }
+
+    private handleInteractionOutput(
+        content: Content,
+        form: TD.Form,
+        outputDataSchema: WoT.DataSchema | undefined
+    ): InteractionOutput {
+        // infer media type from form if not in response metadata
+        content.type ??= form.contentType ?? "application/json";
+
+        // check if returned media type is the same as expected media type (from TD)
+        if (form.response != null) {
+            const parsedMediaTypeContent = ContentType.parse(content.type);
+            const parsedMediaTypeForm = ContentType.parse(form.response.contentType);
+            if (parsedMediaTypeContent.type !== parsedMediaTypeForm.type) {
+                throw new Error(
+                    `Unexpected type '${content.type}' in response. Should be '${form.response.contentType}'`
+                );
+            }
+        }
+        return new InteractionOutput(content, form, outputDataSchema);
     }
 
     async _readProperties(propertyNames: string[]): Promise<WoT.PropertyReadMap> {
@@ -674,19 +702,11 @@ export default class ConsumedThing extends TD.Thing implements IConsumedThing {
         form = this.handleUriVariables(ta, form, options);
 
         const content = await client.invokeResource(form, input);
-        // infer media type from form if not in response metadata
-        if (!content.type) content.type = form.contentType ?? "application/json";
-
-        // check if returned media type is the same as expected media type (from TD)
-        if (form.response != null) {
-            if (content.type !== form.response.contentType) {
-                throw new Error(`Unexpected type in response`);
-            }
-        }
         try {
-            return new InteractionOutput(content, form, ta.output);
-        } catch {
-            throw new Error(`Received invalid content from Thing`);
+            return this.handleInteractionOutput(content, form, ta.output);
+        } catch (e) {
+            const error = e instanceof Error ? e : new Error(JSON.stringify(e));
+            throw new Error(`Error while processing action for ${ta.title}. ${error.message}`);
         }
     }
 
@@ -725,12 +745,11 @@ export default class ConsumedThing extends TD.Thing implements IConsumedThing {
             formWithoutURITemplates,
             // next
             (content) => {
-                // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- tsc get confused when nullables are to listeners lambdas
-                if (!content.type) content.type = form!.contentType ?? "application/json";
                 try {
-                    listener(new InteractionOutput(content, form, tp));
+                    listener(this.handleInteractionOutput(content, form, tp));
                 } catch (e) {
-                    warn(`Error while processing observe event for ${tp.title}`);
+                    const error = e instanceof Error ? e : new Error(JSON.stringify(e));
+                    warn(`Error while processing observe property for ${tp.title}. ${error.message}`);
                     warn(e);
                 }
             },
@@ -782,12 +801,11 @@ export default class ConsumedThing extends TD.Thing implements IConsumedThing {
         await client.subscribeResource(
             formWithoutURITemplates,
             (content) => {
-                // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- tsc get confused when nullables are to listeners lambdas
-                if (!content.type) content.type = form!.contentType ?? "application/json";
                 try {
-                    listener(new InteractionOutput(content, form, te.data));
+                    listener(this.handleInteractionOutput(content, form, te.data));
                 } catch (e) {
-                    warn(`Error while processing event for ${te.title}`);
+                    const error = e instanceof Error ? e : new Error(JSON.stringify(e));
+                    warn(`Error while processing event for ${te.title}. ${error.message}`);
                     warn(e);
                 }
             },

packages/core/src/consumed-thing.ts

@@ -36,6 +36,7 @@ import { Readable } from "stream";
 import { createLoggers, ProtocolHelpers } from "../src/core";
 import { ThingDescription } from "wot-typescript-definitions";
 import chaiAsPromised from "chai-as-promised";
+import { fail } from "assert";
 
 const { debug } = createLoggers("core", "ClientTest");
 
@@ -99,7 +100,13 @@ const myThingDesc = {
         anAction: {
             input: { type: "integer" },
             output: { type: "integer" },
-            forms: [{ href: "testdata://host/athing/actions/anaction", mediaType: "application/json" }],
+            forms: [
+                {
+                    href: "testdata://host/athing/actions/anaction",
+                    mediaType: "application/json",
+                    response: { contentType: "application/json" },
+                },
+            ],
         },
     },
     events: {
@@ -462,6 +469,47 @@ class WoTClientTest {
         expect(value).to.equal(42);
     }
 
+    @test async "call an action with enhanced contentType"() {
+        // an action
+        WoTClientTest.clientFactory.setTrap(async (form: Form, content: Content) => {
+            const valueData = await content.toBuffer();
+            expect(valueData.toString()).to.equal("23");
+            return new Content("application/json; charset=utf-8", Readable.from(Buffer.from("42")));
+        });
+        const td = (await WoTClientTest.WoTHelpers.fetch("td://foo")) as ThingDescription;
+        const thing = await WoTClientTest.WoT.consume(td);
+
+        expect(thing).to.have.property("title").that.equals("aThing");
+        expect(thing).to.have.property("actions").that.has.property("anAction");
+        const result = await thing.invokeAction("anAction", 23);
+        // eslint-disable-next-line no-unused-expressions
+        expect(result).not.to.be.null;
+        const value = await result?.value();
+        expect(value).to.equal(42);
+    }
+
+    @test async "call an action with wrong contentType based on TD response"() {
+        // an action
+        WoTClientTest.clientFactory.setTrap(async (form: Form, content: Content) => {
+            const valueData = await content.toBuffer();
+            expect(valueData.toString()).to.equal("23");
+            // Note: application/json expected based on TD response
+            return new Content("text/plain", Readable.from(Buffer.from("42")));
+        });
+        const td = (await WoTClientTest.WoTHelpers.fetch("td://foo")) as ThingDescription;
+        const thing = await WoTClientTest.WoT.consume(td);
+
+        expect(thing).to.have.property("title").that.equals("aThing");
+        expect(thing).to.have.property("actions").that.has.property("anAction");
+        try {
+            await thing.invokeAction("anAction", 23);
+            fail("Should report unexpected content type");
+        } catch (e) {
+            const error = e instanceof Error ? e : new Error(JSON.stringify(e));
+            expect(error.message).to.contain("type");
+        }
+    }
+
     @test async "subscribe to event"() {
         WoTClientTest.clientFactory.setTrap(() => {
             return new Content("application/json", Readable.from(Buffer.from("triggered")));