Allow backtick around fields in sort cmd (opensearch-project#1688)

* Allow backtick around fields in sort cmd

Signed-off-by: Joshua Li <[email protected]>

* Add test

Signed-off-by: Joshua Li <[email protected]>

* Update test setup

Signed-off-by: Joshua Li <[email protected]>

* revert ignoring sql-cli repo if exists

Signed-off-by: Joshua Li <[email protected]>

---------

Signed-off-by: Joshua Li <[email protected]>
Signed-off-by: Mitchell Gale <[email protected]>

Author: joshuali925

.gitignore

@@ -47,4 +47,6 @@ gen
 
 .java-version
 .worktrees
-http-client.env.json
+http-client.env.json
+/doctest/sql-cli/
+.factorypath

ppl/src/main/java/org/opensearch/sql/ppl/parser/AstExpressionBuilder.java

@@ -182,7 +182,7 @@ public UnresolvedExpression visitWcFieldExpression(WcFieldExpressionContext ctx)
   @Override
   public UnresolvedExpression visitSortField(SortFieldContext ctx) {
     return new Field(
-        qualifiedName(ctx.sortFieldExpression().fieldExpression().getText()),
+        visit(ctx.sortFieldExpression().fieldExpression().qualifiedName()),
         ArgumentFactory.getArgumentList(ctx)
     );
   }

ppl/src/test/java/org/opensearch/sql/ppl/parser/AstExpressionBuilderTest.java

@@ -301,6 +301,15 @@ public void testSortFieldWithMinusKeyword() {
         ));
   }
 
+  @Test
+  public void testSortFieldWithBackticks() {
+    assertEqual("source=t | sort `f`",
+        sort(
+            relation("t"),
+            field("f", defaultSortFieldArgs())
+        ));
+  }
+
   @Test
   public void testSortFieldWithAutoKeyword() {
     assertEqual("source=t | sort auto(f)",