Corrected & renamed Rule E2.1 -> E6

README.md

@@ -43,10 +43,11 @@ As of LAMS v3, you must opt-in via your `manifest.lkml` file to use the built-in
 #rule: F4{} # Description or hidden
 #rule: E1{} # Join with subst'n operator
 #rule: E2{} # Join on PK for "one" joins
+#rule: E6{} # FK joins are m:1
 #rule: T1{} # Triggers use datagroups 
 #rule: T2{} # Primary keys in DT
 #rule: W1{} # Block indentation
-
+#rule: W1{} # Block indentation
 ```
 
 ### Rule Exemptions

__tests__/e6.test.js

@@ -0,0 +1,171 @@
+/* Copyright (c) 2018 Looker Data Sciences, Inc. See https://github.com/looker-open-source/look-at-me-sideways/blob/master/LICENSE.txt */
+require('../lib/expect-to-contain-message');
+
+const rule = require('../rules/e6.js');
+const {parse} = require('lookml-parser');
+
+describe('Rules', () => {
+	describe('E6', () => {
+		let info = {level: 'info'};
+		let error = {level: 'error'};
+		let e6 = {rule: 'E6'};
+
+		it('should not match and pass if there are no models', () => {
+			let result = rule(parse(`file: foo{}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 0 matches, 0 matches exempt, and 0 errors"
+			});
+			expect(result).not.toContainMessage(error);
+		});
+
+		it('should not match and pass if there are no explores', () => {
+			let result = rule(parse(`model: foo {}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 0 matches, 0 matches exempt, and 0 errors"
+			});
+			expect(result).not.toContainMessage(error);
+		});
+
+		it('should not match and pass if there are no joins', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 0 matches, 0 matches exempt, and 0 errors"
+			});
+			expect(result).not.toContainMessage(error);
+		});
+
+		it('should not match and pass for joins without foreign_key', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {
+					join: users {
+						relationship: many_to_one
+					}
+				}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 0 matches, 0 matches exempt, and 0 errors"
+			});
+			expect(result).not.toContainMessage(error);
+		});
+
+		it('should pass for implicit m:1 relationship', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {
+					join: users {
+						foreign_key: user_id
+					}
+				}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 1 matches, 0 matches exempt, and 0 errors"
+			});
+			expect(result).not.toContainMessage(error);
+		});
+
+		it('should pass for explicit m:1 relationship', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {
+					join: users {
+						relationship: many_to_one
+						foreign_key: user_id
+					}
+				}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 1 matches, 0 matches exempt, and 0 errors"
+			});
+			expect(result).not.toContainMessage(error);
+		});
+
+		it('should pass when the FK is the base-view\'s PK and uses 1:1 relationship', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {
+					join: order_derived_columns {
+						relationship: one_to_one
+						foreign_key: pk1_order_id
+					}
+				}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 1 matches, 0 matches exempt, and 0 errors"
+			});
+			expect(result).not.toContainMessage(error);
+		});
+
+		it('should error if a *:m relationship is specified', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {
+					join: users {
+						relationship: one_to_many
+						foreign_key: user_id
+					}
+				}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 1 matches, 0 matches exempt, and 1 errors"
+			});
+			expect(result).toContainMessage({...e6, ...error});
+		});
+
+		it('should error if a 1:1 relationship is specified', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {
+					join: users {
+						relationship: one_to_one
+						foreign_key: user_id
+					}
+				}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 1 matches, 0 matches exempt, and 1 errors"
+			});
+			expect(result).toContainMessage({...e6, ...error});
+		});
+
+		it('should error if a *:m relationship is specified for joins from a pk', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {
+					join: order_derived_columns {
+						relationship: one_to_many
+						foreign_key: pk1_order_id
+					}
+				}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 1 matches, 0 matches exempt, and 1 errors"
+			});
+			expect(result).toContainMessage({...e6, ...error});
+		});
+
+		it('should error if a m:1 relationship is specified for joins from a pk', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {
+					join: order_derived_columns {
+						relationship: many_to_one
+						foreign_key: pk1_order_id
+					}
+				}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 1 matches, 0 matches exempt, and 1 errors"
+			});
+			expect(result).toContainMessage({...e6, ...error});
+		});
+
+		it('should error if a m:1 relationship is implicit for joins from a pk', () => {
+			let result = rule(parse(`model: m {
+				explore: orders {
+					join: order_derived_columns {
+						foreign_key: pk1_order_id
+					}
+				}
+			}`));
+			expect(result).toContainMessage({...e6, ...info,
+				description: "Rule E6 summary: 1 matches, 0 matches exempt, and 1 errors"
+			});
+			expect(result).toContainMessage({...e6, ...error});
+		});
+	});
+});