Fix dialect selector

src/app/__init__.py

@@ -38,7 +38,7 @@ def inject_vars():
         """Inject arbitrary data into all templates."""
         return dict(
             all_rules=config.VALID_RULES,
-            all_dialects=config.VALID_DIALECTS,
+            all_dialects=list(config.VALID_DIALECTS.values()),
             sqlfluff_version=config.SQLFLUFF_VERSION,
         )
 

src/app/config.py

@@ -4,7 +4,7 @@
 
 SQLFLUFF_VERSION = sqlfluff.__version__
 
-VALID_DIALECTS = tuple(d.name for d in sqlfluff.list_dialects())
+VALID_DIALECTS = {d.label: d.name for d in sqlfluff.list_dialects()}
 
 # dict mapping string rule names to descriptions
 VALID_RULES = {r.code: r.description for r in sqlfluff.list_rules()}

src/app/routes.py

@@ -3,6 +3,7 @@
 
 from flask import Blueprint, redirect, render_template, request, url_for
 from sqlfluff.api import fix, lint
+from .config import VALID_DIALECTS
 
 bp = Blueprint("routes", __name__)
 
@@ -43,10 +44,25 @@ def fluff_results():
     sql = sql_decode(request.args["sql"]).strip()
     sql = "\n".join(sql.splitlines()) + "\n"
 
+    # dialect must be a dialect label for `load_raw_dialect`. VALID_DIALECTS is a
+    # dictionary of dialect labels to dialect names. If we have a name, we need to
+    # get the label.
+    #
+    # However, the frontend logic runs on dialect names, so we need to convert the
+    # label back to a name for the frontend.
     dialect = request.args["dialect"]
+    if dialect in VALID_DIALECTS.values():
+        dialect_name = dialect
+        dialect_label = next(
+            label for label, name in VALID_DIALECTS.items() if name == dialect
+        )
+    else:
+        dialect_label = dialect
+        dialect_name = VALID_DIALECTS[dialect]
+
     try:
-        linted = lint(sql, dialect=dialect)
-        fixed_sql = fix(sql, dialect=dialect)
+        linted = lint(sql, dialect=dialect_label)
+        fixed_sql = fix(sql, dialect=dialect_label)
     except RuntimeError as e:
         linted = [
             {
@@ -61,7 +77,7 @@ def fluff_results():
         "index.html",
         results=True,
         sql=sql,
-        dialect=dialect,
+        dialect=dialect_name,
         lint_errors=linted,
         fixed_sql=fixed_sql,
     )

test/test_app.py

@@ -36,15 +36,28 @@ def test_post_redirect(client):
     assert rv.status_code == 302 and "/fluffed?sql" in rv.headers["location"]
 
 
-def test_results_no_errors(client):
-    """Test that the results is good to go when there is no error."""
+@pytest.mark.parametrize("dialect", ["sparksql", "Apache Spark SQL"])
+def test_results_no_errors(client, dialect):
+    """Test that the results is good to go when there is no error.
+
+    Parameterized dialect asserts that either the formatted name or label can be used
+    as the dialect parameter.
+    """
     sql_encoded = sql_encode("select * from table")
-    rv = client.get("/fluffed", query_string=f"""dialect=ansi&sql={sql_encoded}""")
+    rv = client.get("/fluffed", query_string=f"""dialect={dialect}&sql={sql_encoded}""")
     html = rv.data.decode().lower()
     assert "sqlfluff online" in html
     assert "fixed sql" in html
     assert "select * from table" in html
 
+    # Test that the dialect is correctly selected in the results page.
+    selected_dialect = (
+        BeautifulSoup(html, "html.parser")
+        .find("select", {"id": "sql_dialect"})
+        .find("option", {"selected": "selected"})
+    )
+    assert selected_dialect.text.strip() == "apache spark sql"
+
 
 def test_results_some_errors(client):
     """Test that the results is good to go with one obvious error."""