From 59802c78313a013a1ce760d70dbea7450a43d650 Mon Sep 17 00:00:00 2001
From: Steven Turturo <steven@turturo.dev>
Date: Tue, 24 Sep 2024 15:10:25 -0700
Subject: [PATCH] feat: start implementing multi-line formatting for permission
 expressions

---
 pkg/dsl/parser/parser.go      |  5 ++++
 pkg/dsl/parser/parser_test.go | 47 +++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/pkg/dsl/parser/parser.go b/pkg/dsl/parser/parser.go
index 64af42001..4e94a0e40 100644
--- a/pkg/dsl/parser/parser.go
+++ b/pkg/dsl/parser/parser.go
@@ -588,6 +588,11 @@ func (p *Parser) parseExpression(precedence int) (ast.Expression, error) {
 	var exp ast.Expression
 	var err error
 
+	if p.currentTokenIs(token.NEWLINE) {
+		// advance to the next token
+		p.next()
+	}
+
 	if p.currentTokenIs(token.LP) {
 		p.next() // Consume the left parenthesis.
 		exp, err = p.parseExpression(LOWEST)
diff --git a/pkg/dsl/parser/parser_test.go b/pkg/dsl/parser/parser_test.go
index f066c15af..b47b7be28 100644
--- a/pkg/dsl/parser/parser_test.go
+++ b/pkg/dsl/parser/parser_test.go
@@ -849,5 +849,52 @@ var _ = Describe("parser", func() {
 			Expect(es.Expression.(*ast.InfixExpression).Right.(*ast.InfixExpression).Left.(*ast.Identifier).String()).Should(Equal("parent.admin"))
 			Expect(es.Expression.(*ast.InfixExpression).Right.(*ast.InfixExpression).Right.(*ast.Identifier).String()).Should(Equal("parent.member"))
 		})
+
+		It("Case 24 - Multi-line Permission Expression w/ Rule", func() {
+			pr := NewParser(`
+			entity account {
+    			relation owner @user
+    			attribute balance float
+
+    			permission withdraw = check_balance(request.amount, balance) and 
+					owner
+			}
+	
+			rule check_balance(amount float, balance float) {
+				balance >= amount && amount <= 5000
+			}
+			`)
+
+			schema, err := pr.Parse()
+			Expect(err).ShouldNot(HaveOccurred())
+
+			st := schema.Statements[0].(*ast.EntityStatement)
+
+			Expect(st.Name.Literal).Should(Equal("account"))
+
+			r1 := st.RelationStatements[0].(*ast.RelationStatement)
+			Expect(r1.Name.Literal).Should(Equal("owner"))
+
+			for _, a := range r1.RelationTypes {
+				Expect(a.Type.Literal).Should(Equal("user"))
+			}
+
+			a1 := st.AttributeStatements[0].(*ast.AttributeStatement)
+			Expect(a1.Name.Literal).Should(Equal("balance"))
+			Expect(a1.AttributeType.Type.Literal).Should(Equal("float"))
+
+			p1 := st.PermissionStatements[0].(*ast.PermissionStatement)
+			Expect(p1.Name.Literal).Should(Equal("withdraw"))
+
+			es1 := p1.ExpressionStatement.(*ast.ExpressionStatement)
+
+			Expect(es1.Expression.(*ast.InfixExpression).Left.(*ast.Call).String()).Should(Equal("check_balance(request.amount, balance)"))
+			Expect(es1.Expression.(*ast.InfixExpression).Right.(*ast.Identifier).String()).Should(Equal("owner"))
+
+			rs1 := schema.Statements[1].(*ast.RuleStatement)
+
+			Expect(rs1.Name.Literal).Should(Equal("check_balance"))
+			Expect(rs1.Expression).Should(Equal("\nbalance >= amount && amount <= 5000\n\t\t"))
+		})
 	})
 })