Merge pull request #42 from microsoft/unwind_bug_fix

Unwind bug fix

Author: niclasko

flowquery-py/src/parsing/operations/unwind.py

@@ -25,6 +25,10 @@ def as_(self) -> Any:
 
     async def run(self) -> None:
         expression_value = self.expression.value()
+        if expression_value is None:
+            if self.next:
+                self.next.reset()
+            return
         if not isinstance(expression_value, list):
             raise ValueError("Expected array")
         for item in expression_value:

flowquery-py/tests/compute/test_runner.py

@@ -474,6 +474,29 @@ async def test_aggregated_with_and_return(self):
         assert results[0] == {"i": 1, "sum": 12}
         assert results[1] == {"i": 2, "sum": 12}
 
+    @pytest.mark.asyncio
+    async def test_unwind_null_produces_zero_rows(self):
+        """Test that UNWIND null produces zero rows (Neo4j-compatible)."""
+        runner = Runner("WITH null AS x UNWIND x AS i RETURN i")
+        await runner.run()
+        results = runner.results
+        assert len(results) == 0
+
+    @pytest.mark.asyncio
+    async def test_unwind_null_in_pipeline_preserves_no_rows(self):
+        """Test that UNWIND null stops the pipeline producing no rows."""
+        runner = Runner(
+            """
+            WITH null AS arr
+            UNWIND arr AS i
+            UNWIND [1, 2] AS j
+            RETURN i, j
+            """
+        )
+        await runner.run()
+        results = runner.results
+        assert len(results) == 0
+
     @pytest.mark.asyncio
     async def test_aggregated_with_on_empty_result_set(self):
         """Test aggregated with on empty result set does not crash."""

jest.config.js

@@ -4,5 +4,11 @@ module.exports = {
     transform: {
         "^.+.tsx?$": ["ts-jest", {}],
     },
-    testPathIgnorePatterns: ["/node_modules/", "/flowquery-vscode/test/", "/misc/apps/"],
+    testPathIgnorePatterns: [
+        "/node_modules/",
+        "/flowquery-py/",
+        "/flowquery-vscode/",
+        "/docs/",
+        "/misc/",
+    ],
 };

src/parsing/operations/unwind.ts

@@ -1,5 +1,5 @@
-import Operation from "./operation";
 import Expression from "../expressions/expression";
+import Operation from "./operation";
 
 class Unwind extends Operation {
     private _value: any;
@@ -15,10 +15,14 @@ class Unwind extends Operation {
     }
     public async run(): Promise<void> {
         const expression = this.expression.value();
-        if(!(Array.isArray(expression))) {
-            throw new Error('Expected array');
+        if (expression === null || expression === undefined) {
+            this.next?.reset();
+            return;
+        }
+        if (!Array.isArray(expression)) {
+            throw new Error("Expected array");
         }
-        for(let i = 0; i < expression.length; i++) {
+        for (let i = 0; i < expression.length; i++) {
             this._value = expression[i];
             await this.next?.run();
         }
@@ -29,4 +33,4 @@ class Unwind extends Operation {
     }
 }
 
-export default Unwind;
+export default Unwind;

tests/compute/runner.test.ts

@@ -415,6 +415,27 @@ test("Test aggregated with and return", async () => {
     expect(results[1]).toEqual({ i: 2, sum: 12 });
 });
 
+test("Test unwind null produces zero rows", async () => {
+    const runner = new Runner("WITH null AS x UNWIND x AS i RETURN i");
+    await runner.run();
+    const results = runner.results;
+    expect(results.length).toBe(0);
+});
+
+test("Test unwind null in pipeline preserves no rows", async () => {
+    const runner = new Runner(
+        `
+        WITH null AS arr
+        UNWIND arr AS i
+        UNWIND [1, 2] AS j
+        RETURN i, j
+        `
+    );
+    await runner.run();
+    const results = runner.results;
+    expect(results.length).toBe(0);
+});
+
 test("Test aggregated with on empty result set", async () => {
     const runner = new Runner(
         `

tsconfig.json

@@ -3,16 +3,17 @@
     /* Visit https://aka.ms/tsconfig to read more about this file */
     "outDir": "./dist",
     "rootDir": "./src", // Optional, but recommended to specify the root directory
-    "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */    /* Modules */
-    "experimentalDecorators": true,                      /* Enable experimental support for decorators. */
-    "module": "commonjs",                                /* Specify what module code is generated. */
-    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
-    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */
+    "target": "es2016" /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */ /* Modules */,
+    "experimentalDecorators": true /* Enable experimental support for decorators. */,
+    "module": "commonjs" /* Specify what module code is generated. */,
+    "esModuleInterop": true /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */,
+    "forceConsistentCasingInFileNames": true /* Ensure that casing is correct in imports. */,
     "strict": true,
     "types": ["node", "jest"],
     "sourceMap": true,
-    "declaration": true,                                 /* Generate .d.ts declaration files. */
-    "declarationMap": true                               /* Generate sourcemaps for .d.ts files. */
+    "declaration": true /* Generate .d.ts declaration files. */,
+    "declarationMap": true /* Generate sourcemaps for .d.ts files. */
   },
-  "include": ["src"]
-}
+  "include": ["src"],
+  "exclude": ["flowquery-py", "flowquery-vscode", "docs", "misc"]
+}