[FormRecognizer] Fix an issue accessing undefined object

when input document to receipt recognition contains blank pages

sdk/formrecognizer/ai-form-recognizer/.vscode/launch.json

@@ -12,6 +12,7 @@
         "<node_internals>/**"
       ],
       "program": "${file}",
+      "cwd": "${fileDirname}",
       "outFiles": [
         "${workspaceFolder}/dist/**/*.js"
       ]

sdk/formrecognizer/ai-form-recognizer/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## 1.0.0-preview.3 (Unreleased)
 
+- Blank pages in receipt recognition are now handled properly.
+
 ## 1.0.0-preview.2 (2020-05-06)
 
 - `FormTrainingClient.listModels()` now works correctly on NodeJs v8.

sdk/formrecognizer/ai-form-recognizer/src/transforms.ts

@@ -397,7 +397,7 @@ function toRecognizedReceipt(result: DocumentResultModel, pages: FormPage[]): Re
   const form = toRecognizedForm(result, pages);
   return {
     recognizedForm: form,
-    locale: undefined
+    locale: undefined // in the future service would return locale info
   };
 }
 
@@ -506,11 +506,17 @@ export function toReceiptResultResponse(
     return common;
   }
 
+  if (!result.analyzeResult) {
+    throw new Error("Expecting valid analyzeResult from the service response")
+  }
+
   const pages = result.analyzeResult!.readResults.map(toFormPage);
   return {
     ...common,
     version: result.analyzeResult!.version,
-    receipts: result.analyzeResult!.documentResults!.map((d) => {
+    receipts: result.analyzeResult!.documentResults!.filter(d => {
+      return !!d.fields
+    }).map((d) => {
       const receipt = toRecognizedReceipt(d, pages);
       return toReceiptWithLocale({ ...receipt, locale: "US" }); // default to US until service returns locale info.
     })

sdk/formrecognizer/ai-form-recognizer/test/node/formrecognizerclient.spec.ts

@@ -185,4 +185,27 @@ describe("FormRecognizerClient NodeJS only", () => {
     const usReceipt = response!.receipts![0];
     assert.equal(usReceipt.recognizedForm.formType, "prebuilt:receipt");
   });
+
+  it("recognizes multi-page receipt with blank page", async () => {
+    const filePath = path.join(ASSET_PATH, "receipt", "multipage_invoice1.pdf");
+    const stream = fs.createReadStream(filePath);
+
+    const poller = await client.beginRecognizeReceipts(stream, "application/pdf", {
+      includeTextDetails: true
+    });
+    await poller.pollUntilDone();
+    const response = poller.getResult();
+
+    assert.ok(response, "Expect valid response object");
+    assert.equal(response!.status, "succeeded");
+    assert.ok(
+      response!.receipts && response!.receipts.length > 0,
+      `Expect no-empty pages but got ${response!.receipts}`
+    );
+    const usReceipt = response!.receipts![0];
+    assert.equal(usReceipt.recognizedForm.formType, "prebuilt:receipt");
+    assert.equal(usReceipt.locale, "US"); // default to "US" for now
+    assert.equal(usReceipt.receiptType, "itemized");
+    assert.equal(usReceipt.locale, "US");
+  });
 }).timeout(60000);

sdk/formrecognizer/ai-form-recognizer/test/transforms.spec.ts

@@ -14,15 +14,17 @@ import {
   toFormTable,
   toRecognizeFormResultResponse,
   toReceiptResultResponse,
-  toFormModelResponse
+  toFormModelResponse,
+  toRecognizedForm
 } from "../src/transforms";
 import {
   GeneratedClientGetAnalyzeFormResultResponse as GetAnalyzeFormResultResponse,
   GeneratedClientGetAnalyzeReceiptResultResponse as GetAnalyzeReceiptResultResponse,
   GeneratedClientGetCustomModelResponse as GetCustomModelResponse,
   ReadResult as ReadResultModel,
   FieldValue as FieldValueModel,
-  DataTable as DataTableModel
+  DataTable as DataTableModel,
+  DocumentResult as DocumentResultModel
 } from "../src/generated/models";
 import {
   StringFieldValue,
@@ -456,6 +458,19 @@ describe("Transforms", () => {
     assert.equal(transformed.rows[2].cells[0].columnSpan, 2);
   });
 
+  it("toRecognizedForm() should handle empty page", () => {
+    const original: DocumentResultModel = {
+      docType: "prebuilt:receipt",
+      pageRange: [1, 1],
+      fields: {}
+    }
+
+    const transformed = toRecognizedForm(original, formPages);
+
+    assert.ok(transformed, "Expected valid recognized form");
+    assert.deepStrictEqual(transformed.fields, {}, "expected empty fields in recognzied form");
+  });
+
   it("toRecognizeFormResultResponse() converts unsupervised response into recognized forms", () => {
     const original: GetAnalyzeFormResultResponse = JSON.parse(unsupervisedResponseString);
     const transformed = toRecognizeFormResultResponse(original);