Fix v and nv filters in SQL (#340)

Author: Annie Zhang

src/table.js

@@ -380,13 +380,17 @@ function appendWhereEntry({type, operands}, args, escaper) {
   if (operands.length < 1) throw new Error("Invalid operand length");
 
   // Unary operations
-  if (operands.length === 1) {
+  // We treat `v` and `nv` as `NULL` and `NOT NULL` unary operations in SQL,
+  // since the database already validates column types.
+  if (operands.length === 1 || type === "v" || type === "nv") {
     appendOperand(operands[0], args, escaper);
     switch (type) {
       case "n":
+      case "nv":
         appendSql(` IS NULL`, args);
         return;
       case "nn":
+      case "v":
         appendSql(` IS NOT NULL`, args);
         return;
       default:
@@ -398,7 +402,7 @@ function appendWhereEntry({type, operands}, args, escaper) {
   if (operands.length === 2) {
     if (["in", "nin"].includes(type)) {
       // Fallthrough to next parent block.
-    } else if (["c", "nc", "v", "nv"].includes(type)) {
+    } else if (["c", "nc"].includes(type)) {
       // TODO: Case (in)sensitive?
       appendOperand(operands[0], args, escaper);
       switch (type) {
@@ -408,14 +412,6 @@ function appendWhereEntry({type, operands}, args, escaper) {
         case "nc":
           appendSql(` NOT LIKE `, args);
           break;
-        // JavaScript "not valid" filter translate to a SQL "IS NULL"
-        case "nv":
-          appendSql(` IS NULL`, args);
-          break;
-        // JavaScript "valid" filter translate to a SQL "IS NOT NULL"
-        case "v":
-          appendSql(` IS NOT NULL`, args);
-          break;
       }
       appendOperand(likeOperand(operands[1]), args, escaper);
       return;

test/table-test.js

@@ -182,6 +182,31 @@ describe("makeQueryTemplate", () => {
     assert.deepStrictEqual(params, ["val1", "val2", "val3", "val4"]);
   });
 
+  it("makeQueryTemplate filter valid and not valid", () => {
+    const source = {name: "db", dialect: "postgres"};
+    const operations = {
+      ...baseOperations,
+      filter: [
+        {
+          type: "v",
+          operands: [
+            {type: "column", value: "col1"},
+            {type: "primitive", value: "string"}
+          ]
+        },
+        {
+          type: "nv",
+          operands: [
+            {type: "column", value: "col2"},
+            {type: "primitive", value: "number"}
+          ]
+        }
+      ]
+    };
+    const [parts] = makeQueryTemplate(operations, source);
+    assert.deepStrictEqual(parts.join("?"), "SELECT col1, col2 FROM table1\nWHERE col1 IS NOT NULL\nAND col2 IS NULL");
+  });
+
   it("makeQueryTemplate select", () => {
     const source = {name: "db", dialect: "mysql"};
     const operations = {