odata-filter: remove no-op case-change of function name (#1237)

odata-v4-parser treats function names as case-sensitive, so non-lowercase extractFunction names ever reach here

lib/data/odata-filter.js

@@ -27,10 +27,9 @@ const odataFilter = (expr, odataToColumnMap) => {
   const methodCall = (node) => {
     // n.b. odata-v4-parser appears to already validate function name and arity.
     const fn = node.value.method;
-    const lowerName = fn.toLowerCase();
     const params = node.value.parameters;
-    if (extractFunctions.includes(lowerName)) {
-      return sql`extract(${sql.identifier([lowerName])} from ${op(params[0])})`; // eslint-disable-line no-use-before-define
+    if (extractFunctions.includes(fn)) {
+      return sql`extract(${sql.identifier([fn])} from ${op(params[0])})`; // eslint-disable-line no-use-before-define
     } else if (fn === 'now') {
       return sql`now()`;
     } else {

test/unit/data/odata-filter.js

@@ -75,14 +75,29 @@ describe('OData filter query transformer', () => {
     });
   });
 
-  it('should reject unrecognized function names', () => {
+  it('should reject unsupported OData functions', () => {
     assert.throws(() => { odataFilter('123 eq trim(\' 123 \')'); }, (err) => {
       err.should.be.a.Problem();
       err.problemCode.should.equal(501.4);
       err.message.should.equal('The given OData filter expression uses features not supported by this server: MethodCallExpression at 7 ("trim(\' 123 \')")');
       return true;
     });
   });
+
+  [
+    'somethingwhichneverexisted()',
+    'NOW()', // wrong case
+    'YEAR(now())', // wrong case
+  ].forEach(badCall => {
+    it(`should reject unrecognized function name ${badCall}`, () => {
+      assert.throws(() => { odataFilter(`123 eq ${badCall}`); }, (err) => {
+        err.should.be.a.Problem();
+        err.problemCode.should.equal(400.18);
+        err.message.should.match(/^The OData filter expression you provided could not be parsed: Unexpected character at \d+$/);
+        return true;
+      });
+    });
+  });
 });
 
 describe('OData orderby/sort query transformer', () => {