fix(csv2json,historical): dividends/csv with no data (fixes #658)

src/lib/csv2json.spec.ts

@@ -25,10 +25,13 @@ describe("csv2json", () => {
     expect(obj[0].string).toBeType("string");
   });
 
+  /*
+  actually, one line files are ok... headers and no data.
   it("throws on weird file (no newlines)", () => {
     const csv = "one line file";
     expect(() => csv2json(csv)).toThrow(/No newlines/);
   });
+  */
 
   it("handles nulls", () => {
     const obj = csv2json("val\nnull")[0];

src/lib/csv2json.ts

@@ -21,7 +21,10 @@ function convert(input: any) {
 
 export default function csv2json(csv: string): Array<any> {
   const lines = csv.split("\n");
-  if (lines.length === 1) throw new Error("No newlines in: " + csv);
+
+  // Actually we should handle this case, i.e. headers but no data.
+  // if (lines.length === 1)
+  //  throw new Error("No newlines in: " + csv);
 
   const headers = (lines.shift() as string).split(DELIMITER).map(camelize);
   const out = new Array(lines.length);

src/modules/historical.spec.ts

@@ -122,4 +122,18 @@ describe("historical", () => {
         ).rejects.toThrow("SOME (but not all) null values");
       });
   });
+
+  it("handles events:dividends for stocks with no dividends (#658)", async () => {
+    const data = await yf.historical(
+      "TSLA", // No dividends at time of writing
+      {
+        period1: 0,
+        period2: "2023-08-12", // time of writing :)
+        events: "dividends",
+        interval: "1d",
+      },
+      { devel: "historical-dividends-TSLA-no-dividends.json" }
+    );
+    // Enough to check that this doesn't throw.
+  });
 });

src/modules/historical.ts

@@ -154,6 +154,8 @@ export default function historical(
     result: {
       schemaKey,
       transformWith(result: any) {
+        if (result.length === 0) return result;
+
         const filteredResults = [];
         const fieldCount = Object.keys(result[0]).length;
 

tests/http/historical-dividends-TSLA-no-dividends.json

@@ -0,0 +1,73 @@
+{
+  "request": {
+    "url": "https://query2.finance.yahoo.com/v7/finance/download/TSLA?interval=1d&events=dividends&includeAdjustedClose=true&period1=0&period2=1691798400"
+  },
+  "response": {
+    "ok": true,
+    "status": 200,
+    "statusText": "OK",
+    "headers": {
+      "content-disposition": [
+        "attachment; filename=TSLA.csv"
+      ],
+      "content-type": [
+        "text/csv;charset=utf-8"
+      ],
+      "vary": [
+        "Origin"
+      ],
+      "cache-control": [
+        "private, max-age=10, stale-while-revalidate=20"
+      ],
+      "y-rid": [
+        "06jo791idekh9"
+      ],
+      "x-yahoo-request-id": [
+        "06jo791idekh9"
+      ],
+      "x-request-id": [
+        "e96cb916-7317-4b22-81af-105251e06cec"
+      ],
+      "content-length": [
+        "14"
+      ],
+      "x-envoy-upstream-service-time": [
+        "20"
+      ],
+      "date": [
+        "Sat, 12 Aug 2023 09:34:33 GMT"
+      ],
+      "server": [
+        "ATS"
+      ],
+      "x-envoy-decorator-operation": [
+        "finance-chart-api--mtls-production-ir2.finance-k8s.svc.yahoo.local:4080/*"
+      ],
+      "age": [
+        "0"
+      ],
+      "strict-transport-security": [
+        "max-age=31536000"
+      ],
+      "referrer-policy": [
+        "no-referrer-when-downgrade"
+      ],
+      "x-frame-options": [
+        "SAMEORIGIN"
+      ],
+      "connection": [
+        "close"
+      ],
+      "expect-ct": [
+        "max-age=31536000, report-uri=\"http://csp.yahoo.com/beacon/csp?src=yahoocom-expect-ct-report-only\""
+      ],
+      "x-xss-protection": [
+        "1; mode=block"
+      ],
+      "x-content-type-options": [
+        "nosniff"
+      ]
+    },
+    "body": "Date,Dividends"
+  }
+}