added some unit tests for the discount fn

Author: nickwesselman

sample-apps/discounts/extensions/product-discount/src/tests.rs

@@ -2,11 +2,22 @@ use super::*;
 use shopify_function::{run_function_with_input, Result};
 
 #[test]
-fn test_result_contains_no_discounts() -> Result<()> {
+fn test_no_metafield_result_contains_no_discounts() -> Result<()> {
     let result = run_function_with_input(
         function,
         r#"
             {
+                "cart": {
+                    "lines": [
+                        {
+                            "quantity": 10,
+                            "merchandise": {
+                                "__typename": "ProductVariant",
+                                "id": "gid://shopify/ProductVariant/123456789"
+                            }
+                        }
+                    ]
+                },
                 "discountNode": {
                     "metafield": null
                 }
@@ -18,3 +29,99 @@ fn test_result_contains_no_discounts() -> Result<()> {
     assert_eq!(result.discounts.len(), expected);
     Ok(())
 }
+
+#[test]
+fn test_quantity_unmet_result_contains_no_discounts() -> Result<()> {
+    let result = run_function_with_input(
+        function,
+        r#"
+            {
+                "cart": {
+                    "lines": [
+                        {
+                            "quantity": 1,
+                            "merchandise": {
+                                "__typename": "ProductVariant",
+                                "id": "gid://shopify/ProductVariant/123456789"
+                            }
+                        }
+                    ]
+                },
+                "discountNode": {
+                    "metafield": {
+                        "value": "{\"quantity\":2,\"percentage\":5}"
+                    }
+                }
+            }
+        "#,
+    )?;
+    let expected = 0;
+
+    assert_eq!(result.discounts.len(), expected);
+    Ok(())
+}
+
+#[test]
+fn test_quantity_met_discounts_variants() -> Result<()> {
+    let result = run_function_with_input(
+        function,
+        r#"
+            {
+                "cart": {
+                    "lines": [
+                        {
+                            "quantity": 2,
+                            "merchandise": {
+                                "__typename": "ProductVariant",
+                                "id": "gid://shopify/ProductVariant/123456789"
+                            }
+                        },
+                        {
+                            "quantity": 3,
+                            "merchandise": {
+                                "__typename": "ProductVariant",
+                                "id": "gid://shopify/ProductVariant/987654321"
+                            }
+                        }
+                    ]
+                },
+                "discountNode": {
+                    "metafield": {
+                        "value": "{\"quantity\":2,\"percentage\":5}"
+                    }
+                }
+            }
+        "#,
+    )?;
+    let expected = output::FunctionResult {
+        discount_application_strategy: output::DiscountApplicationStrategy::FIRST,
+        discounts: vec![
+            output::Discount {
+                message: None,
+                targets: vec![
+                    output::Target {
+                        product_variant: Some(output::ProductVariantTarget {
+                            id: "gid://shopify/ProductVariant/123456789".to_string(),
+                            quantity: None
+                        })
+                    },
+                    output::Target {
+                        product_variant: Some(output::ProductVariantTarget {
+                            id: "gid://shopify/ProductVariant/987654321".to_string(),
+                            quantity: None
+                        })
+                    },
+                ],
+                value: output::Value {
+                    fixed_amount: None,
+                    percentage: Some(output::Percentage {
+                        value: "5".to_string()
+                    })
+                }
+            }
+        ]
+    };
+
+    assert_eq!(result, expected);
+    Ok(())
+}