#0 Filter invalid symbols to allow partial responses

src/main/java/dev/sorn/fmp4j/json/FmpJsonModule.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import dev.sorn.fmp4j.types.FmpIsin;
+import dev.sorn.fmp4j.types.FmpSymbol;
 
 public final class FmpJsonModule extends SimpleModule {
 
@@ -10,5 +11,6 @@ public final class FmpJsonModule extends SimpleModule {
     public FmpJsonModule() {
         super(FMP_JSON_MODULE_NAME);
         this.addDeserializer(FmpIsin.class, new FmpJsonBlankAsNullStringDeserializer<>(FmpIsin::isin));
+        this.addDeserializer(FmpSymbol.class, new FmpSymbolDeserializer());
     }
 }

src/main/java/dev/sorn/fmp4j/json/FmpSymbolDeserializer.java

@@ -0,0 +1,26 @@
+package dev.sorn.fmp4j.json;
+
+import static dev.sorn.fmp4j.types.FmpSymbol.symbol;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import dev.sorn.fmp4j.exceptions.FmpInvalidSymbolException;
+import dev.sorn.fmp4j.types.FmpSymbol;
+import java.io.IOException;
+
+public class FmpSymbolDeserializer extends JsonDeserializer<FmpSymbol> {
+    @Override
+    public FmpSymbol deserialize(JsonParser p, DeserializationContext ctx) throws IOException {
+        String value = p.getText();
+        if (value == null || value.trim().isEmpty()) {
+            return null; // or skip
+        }
+        try {
+            return symbol(value);
+        } catch (FmpInvalidSymbolException e) {
+            System.err.printf("Invalid symbol skipped: %s%n", value);
+            return null;
+        }
+    }
+}

src/main/java/dev/sorn/fmp4j/services/FmpService.java

@@ -31,6 +31,10 @@ protected final URI url() {
 
     protected abstract Set<String> optionalParams();
 
+    protected R filter(R r) {
+        return r;
+    }
+
     public final void param(String key, Object value) {
         if (!requiredParams().contains(key) && !optionalParams().contains(key)) {
             throw new FmpServiceException("'%s' is not a recognized query param for endpoint [%s]", key, url());
@@ -49,6 +53,6 @@ public final R download() {
                 throw new FmpServiceException("'%s' is a required query param for endpoint [%s]", req, url());
             }
         }
-        return http.get(typeRef, url(), headers(), params);
+        return filter(http.get(typeRef, url(), headers(), params));
     }
 }

src/main/java/dev/sorn/fmp4j/services/FmpStockListService.java

@@ -1,6 +1,7 @@
 package dev.sorn.fmp4j.services;
 
 import static dev.sorn.fmp4j.json.FmpJsonUtils.typeRef;
+import static java.util.Arrays.stream;
 import static java.util.Collections.emptySet;
 
 import dev.sorn.fmp4j.cfg.FmpConfig;
@@ -27,4 +28,9 @@ protected Set<String> requiredParams() {
     protected Set<String> optionalParams() {
         return emptySet();
     }
+
+    @Override
+    protected FmpStock[] filter(FmpStock[] stocks) {
+        return stream(stocks).filter(s -> s.symbol() != null).toArray(FmpStock[]::new);
+    }
 }

src/test/java/dev/sorn/fmp4j/json/FmpSymbolDeserializerTest.java

@@ -0,0 +1,70 @@
+package dev.sorn.fmp4j.json;
+
+import static dev.sorn.fmp4j.types.FmpSymbol.symbol;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import java.io.IOException;
+import org.junit.jupiter.api.Test;
+
+class FmpSymbolDeserializerTest {
+    private final JsonParser p = mock(JsonParser.class);
+    private final DeserializationContext ctx = mock(DeserializationContext.class);
+    private final FmpSymbolDeserializer deserializer = new FmpSymbolDeserializer();
+
+    @Test
+    void deserialize_null_symbol_returns_null() throws IOException {
+        // given
+        var nullStr = (String) null;
+
+        // when
+        when(p.getText()).thenReturn(nullStr);
+        var result = deserializer.deserialize(p, ctx);
+
+        // then
+        assertNull(result);
+    }
+
+    @Test
+    void deserialize_blank_symbol_returns_null() throws IOException {
+        // given
+        var blank = "";
+
+        // when
+        when(p.getText()).thenReturn(blank);
+        var result = deserializer.deserialize(p, ctx);
+
+        // then
+        assertNull(result);
+    }
+
+    @Test
+    void deserialize_invalid_symbol_returns_null() throws IOException {
+        // given
+        var invalid = "$INVALID";
+
+        // when
+        when(p.getText()).thenReturn(invalid);
+        var result = deserializer.deserialize(p, ctx);
+
+        // then
+        assertNull(result);
+    }
+
+    @Test
+    void deserialize_valid_symbol_returns_symbol() throws IOException {
+        // given
+        var symbol = "AAPL";
+
+        // when
+        when(p.getText()).thenReturn(symbol);
+        var result = deserializer.deserialize(p, ctx);
+
+        // then
+        assertEquals(symbol("AAPL"), result);
+    }
+}

src/test/java/dev/sorn/fmp4j/services/FmpStockListServiceTest.java

@@ -64,4 +64,21 @@ void successful_download() {
         range(0, 2).forEach(i -> assertInstanceOf(FmpStock.class, result[i]));
         range(0, 2).forEach(i -> assertAllFieldsNonNull(result[i]));
     }
+
+    @Test
+    void partial_successful_download() {
+        // given
+        httpStub.configureResponse()
+                .body(jsonTestResource("stable/stock-list/contains_invalid.json"))
+                .statusCode(200)
+                .apply();
+
+        // when
+        var result = service.download();
+
+        // then
+        assertEquals(2, result.length);
+        range(0, 2).forEach(i -> assertInstanceOf(FmpStock.class, result[i]));
+        range(0, 2).forEach(i -> assertAllFieldsNonNull(result[i]));
+    }
 }

src/testFixtures/resources/stable/stock-list/contains_invalid.json

@@ -0,0 +1,14 @@
+[
+  {
+    "symbol": "6898.HK",
+    "companyName": "China Aluminum Cans Holdings Limited"
+  },
+  {
+    "symbol": "0700.HK",
+    "companyName": "Tencent Holdings Limited"
+  },
+  {
+    "symbol": "$INVALID",
+    "companyName": "Some Invalid Company Limited"
+  }
+]