feat: implement function if

josdejong · josdejong · commit 2be6115a6ef7 · 2024-11-12T09:39:48.000+01:00
diff --git a/docs/index.html b/docs/index.html
@@ -200,6 +200,11 @@ <h1>JSON Query</h1>
                      href="https://github.com/jsonquerylang/jsonquery/blob/main/reference/functions.md#exists"
                      target="_blank"><code>exists(property)</code></a>
                 </li>
+                <li>
+                  <a title="if"
+                     href="https://github.com/jsonquerylang/jsonquery/blob/main/reference/functions.md#if"
+                     target="_blank"><code>if(condition, valueIfTrue, valueIfFalse)</code></a>
+                </li>
                 <li>
                   <a title="regex"
                      href="https://github.com/jsonquerylang/jsonquery/blob/main/reference/functions.md#regex"
diff --git a/reference/functions.md b/reference/functions.md
@@ -827,6 +827,32 @@ jsonquery({ "value": null }, ["exists", "value"]) // true
 jsonquery({ "value": undefined }, ["exists", "value"]) // false
 ```
 
+## if
+
+A conditional allowing to make a choice depending on a condition. Both `then` and `else` parts are required.
+
+```text
+if(condition, valueIfTrue, valueIfFalse)
+```
+
+Example:
+
+```js
+const data = {
+  "kid": {
+    "name": "Emma", 
+    "age": 11
+  },
+  "minAge": 12,
+  "messageOk": "Welcome!",
+  "messageFail": "Sorry, you're too young."
+}
+
+jsonquery(data, 'if(.kid.age >= .minAge, .messageOk, .messageFail)')
+// "Sorry, you're too young."
+```
+
+
 ## in
 
 Test whether the search value is one of the values of the provided list.
diff --git a/src/functions.ts b/src/functions.ts
@@ -221,6 +221,13 @@ export const functions: FunctionBuildersMap = {
       return !!parent && Object.hasOwnProperty.call(parent, key)
     }
   },
+  if: (condition: JSONQuery, valueIfTrue: JSONQuery, valueIfFalse: JSONQuery) => {
+    const _condition = compile(condition)
+    const _valueIfTrue = compile(valueIfTrue)
+    const _valueIfFalse = compile(valueIfFalse)
+
+    return (data: unknown) => (_condition(data) ? _valueIfTrue(data) : _valueIfFalse(data))
+  },
 
   eq: buildFunction((a, b) => a === b),
   gt: buildFunction((a, b) => a > b),
diff --git a/test-suite/compile.test.json b/test-suite/compile.test.json
@@ -897,6 +897,60 @@
       "output": false
     },
 
+    {
+      "category": "if",
+      "description": "should calculate if (1)",
+      "input": {
+        "status": true,
+        "messageOk": "Welcome!",
+        "messageFail": "Sorry, you're too young"
+      },
+      "query": ["if", ["get", "status"], ["get", "messageOk"], ["get", "messageFail"]],
+      "output": "Welcome!"
+    },
+    {
+      "category": "if",
+      "description": "should calculate if (2)",
+      "input": null,
+      "query": ["if", true, true, false],
+      "output": true
+    },
+    {
+      "category": "if",
+      "description": "should calculate if (3)",
+      "input": null,
+      "query": ["if", false, true, false],
+      "output": false
+    },
+    {
+      "category": "if",
+      "description": "should calculate if (4)",
+      "input": null,
+      "query": ["if", 1, true, false],
+      "output": true
+    },
+    {
+      "category": "if",
+      "description": "should calculate if (5)",
+      "input": null,
+      "query": ["if", 0, true, false],
+      "output": false
+    },
+    {
+      "category": "if",
+      "description": "should calculate if (6)",
+      "input": null,
+      "query": ["if", "message", true, false],
+      "output": true
+    },
+    {
+      "category": "if",
+      "description": "should calculate if (7)",
+      "input": null,
+      "query": ["if", "", true, false],
+      "output": false
+    },
+
     {
       "category": "in",
       "description": "should calculate in (1)",
