fix(funcspec): remove AllowQueryParamFilters and related logic

* Simplify SqlQueryOptions by removing AllowQueryParamFilters
* Update mergeQueryParams to avoid applying filters for JSON arguments
* Add tests for sqlStripStringLiterals and query param handling

pkg/funcspec/function_api_test.go

@@ -851,6 +851,231 @@ func TestReplaceMetaVariables(t *testing.T) {
 	}
 }
 
+// TestSqlStripStringLiterals tests that single-quoted string literals are removed
+func TestSqlStripStringLiterals(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "No string literals",
+			input:    "SELECT rid, rid_parent FROM users",
+			expected: "SELECT rid, rid_parent FROM users",
+		},
+		{
+			name:     "Simple string literal",
+			input:    "SELECT * FROM users WHERE mode = 'admin'",
+			expected: "SELECT * FROM users WHERE mode = ''",
+		},
+		{
+			name:     "JSON argument containing column names",
+			input:    `SELECT rid, rid_parent FROM crm_get_menu(1,'mode', '{"rid_parent":"[rid_parent]","CF:STARTDATE":"[cf_startdate]"}')`,
+			expected: `SELECT rid, rid_parent FROM crm_get_menu(1,'', '')`,
+		},
+		{
+			name:     "Escaped single quotes inside literal",
+			input:    "SELECT * FROM t WHERE name = 'O''Brien'",
+			expected: "SELECT * FROM t WHERE name = ''",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := sqlStripStringLiterals(tt.input)
+			if result != tt.expected {
+				t.Errorf("sqlStripStringLiterals() =\n  %q\nwant\n  %q", result, tt.expected)
+			}
+		})
+	}
+}
+
+// TestAllowFilterDoesNotMatchInsideJsonArgument verifies that AllowFilter will add WHERE
+// clauses for real output columns (rid, rid_parent) but not for names that only appear
+// inside a JSON string argument (cf_startdate, cf_rid_branch).
+func TestAllowFilterDoesNotMatchInsideJsonArgument(t *testing.T) {
+	handler := NewHandler(&MockDatabase{})
+
+	sqlQuery := `select rid, rid_parent, description
+      from crm_get_menu([rid_user],'[p_mode]', 0, '', '{"rid_parent":"[rid_parent]", "CF:STARTDATE": "[cf_startdate]", "CF:RID_BRANCH": "[cf_rid_branch]"}')`
+
+	tests := []struct {
+		name        string
+		queryParams map[string]string
+		checkResult func(t *testing.T, result string)
+	}{
+		{
+			name:        "rid_parent=0 is a real column — filter applied",
+			queryParams: map[string]string{"rid_parent": "0"},
+			checkResult: func(t *testing.T, result string) {
+				if !strings.Contains(strings.ToLower(result), "where") {
+					t.Error("Expected WHERE clause to be added for rid_parent")
+				}
+				if !strings.Contains(result, "rid_parent = 0 OR") && !strings.Contains(result, "rid_parent IS NULL") {
+					t.Errorf("Expected null-safe filter for rid_parent=0, got:\n%s", result)
+				}
+			},
+		},
+		{
+			name:        "cf_startdate only appears in JSON string — no filter applied",
+			queryParams: map[string]string{"cf_startdate": "2024-01-01"},
+			checkResult: func(t *testing.T, result string) {
+				if strings.Contains(strings.ToLower(result), "where") {
+					t.Errorf("Expected no WHERE clause for cf_startdate (only in JSON arg), got:\n%s", result)
+				}
+			},
+		},
+		{
+			name:        "cf_rid_branch only appears in JSON string — no filter applied",
+			queryParams: map[string]string{"cf_rid_branch": "5"},
+			checkResult: func(t *testing.T, result string) {
+				if strings.Contains(strings.ToLower(result), "where") {
+					t.Errorf("Expected no WHERE clause for cf_rid_branch (only in JSON arg), got:\n%s", result)
+				}
+			},
+		},
+		{
+			name:        "description is a real column — filter applied",
+			queryParams: map[string]string{"description": "test"},
+			checkResult: func(t *testing.T, result string) {
+				if !strings.Contains(strings.ToLower(result), "where") {
+					t.Error("Expected WHERE clause for description")
+				}
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req := createTestRequest("GET", "/test", tt.queryParams, nil, nil)
+			variables := make(map[string]interface{})
+			propQry := make(map[string]string)
+
+			result := handler.mergeQueryParams(req, sqlQuery, variables, true, propQry)
+			tt.checkResult(t, result)
+		})
+	}
+}
+
+// TestGetReplacementForBlankParamDoubleQuote verifies that placeholders surrounded by
+// double quotes (as in JSON string values) are blanked to "" not NULL.
+func TestGetReplacementForBlankParamDoubleQuote(t *testing.T) {
+	tests := []struct {
+		name     string
+		sqlQuery string
+		param    string
+		expected string
+	}{
+		{
+			name:     "Parameter in double quotes (JSON value)",
+			sqlQuery: `SELECT * FROM f(1, '{"key":"[myparam]"}')`,
+			param:    "[myparam]",
+			expected: "",
+		},
+		{
+			name:     "Parameter not in any quotes",
+			sqlQuery: `SELECT * FROM f([myparam])`,
+			param:    "[myparam]",
+			expected: "NULL",
+		},
+		{
+			name:     "Parameter in single quotes",
+			sqlQuery: `SELECT * FROM f('[myparam]')`,
+			param:    "[myparam]",
+			expected: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := getReplacementForBlankParam(tt.sqlQuery, tt.param)
+			if result != tt.expected {
+				t.Errorf("getReplacementForBlankParam() = %q, want %q\nquery: %s", result, tt.expected, tt.sqlQuery)
+			}
+		})
+	}
+}
+
+// TestVariableReplacementFromQueryParams verifies that query params matching [placeholder]
+// tokens are substituted even when they don't have the p- prefix.
+func TestVariableReplacementFromQueryParams(t *testing.T) {
+	handler := NewHandler(&MockDatabase{})
+
+	sqlQuery := `select rid, rid_parent from crm_get_menu([rid_user],'[p_mode]', 0, '', '{"rid_parent":"[rid_parent]","CF:STARTDATE":"[cf_startdate]"}')`
+
+	tests := []struct {
+		name        string
+		queryParams map[string]string
+		checkResult func(t *testing.T, result string)
+	}{
+		{
+			name:        "rid_parent replaced from query param",
+			queryParams: map[string]string{"rid_parent": "42"},
+			checkResult: func(t *testing.T, result string) {
+				if strings.Contains(result, "[rid_parent]") {
+					t.Errorf("Expected [rid_parent] to be replaced, still present in:\n%s", result)
+				}
+				if !strings.Contains(result, "42") {
+					t.Errorf("Expected value 42 in query, got:\n%s", result)
+				}
+			},
+		},
+		{
+			name:        "cf_startdate replaced from query param",
+			queryParams: map[string]string{"cf_startdate": "2024-01-01"},
+			checkResult: func(t *testing.T, result string) {
+				if strings.Contains(result, "[cf_startdate]") {
+					t.Errorf("Expected [cf_startdate] to be replaced, still present in:\n%s", result)
+				}
+				if !strings.Contains(result, "2024-01-01") {
+					t.Errorf("Expected date value in query, got:\n%s", result)
+				}
+			},
+		},
+		{
+			name:        "missing param blanked to empty string inside JSON (double-quoted)",
+			queryParams: map[string]string{},
+			checkResult: func(t *testing.T, result string) {
+				// [cf_startdate] is surrounded by " in the JSON — should blank to ""
+				if strings.Contains(result, "[cf_startdate]") {
+					t.Errorf("Expected [cf_startdate] to be blanked, still present in:\n%s", result)
+				}
+				if strings.Contains(result, "NULL") && strings.Contains(result, "cf_startdate") {
+					t.Errorf("Expected empty string (not NULL) for double-quoted placeholder, got:\n%s", result)
+				}
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			inputvars := make([]string, 0)
+			q := handler.extractInputVariables(sqlQuery, &inputvars)
+
+			req := createTestRequest("GET", "/test", tt.queryParams, nil, nil)
+			variables := make(map[string]interface{})
+			propQry := make(map[string]string)
+
+			q = handler.mergeQueryParams(req, q, variables, false, propQry)
+
+			// Simulate the variable replacement + blank-param loop (mirrors function_api.go)
+			for _, kw := range inputvars {
+				varName := kw[1 : len(kw)-1]
+				if val, ok := variables[varName]; ok {
+					if strVal := strings.TrimSpace(val.(string)); strVal != "" {
+						q = strings.ReplaceAll(q, kw, ValidSQL(strVal, "colvalue"))
+						continue
+					}
+				}
+				replacement := getReplacementForBlankParam(q, kw)
+				q = strings.ReplaceAll(q, kw, replacement)
+			}
+
+			tt.checkResult(t, q)
+		})
+	}
+}
+
 // TestGetReplacementForBlankParam tests the blank parameter replacement logic
 func TestGetReplacementForBlankParam(t *testing.T) {
 	tests := []struct {