Add #dumpContext tag (#113)

* add dumpContext tag

* remove additional context data in test

Co-authored-by: Marius Seufzer <marius.seufzer@protonmail.com>
Co-authored-by: Tim Condon <0xTim@users.noreply.github.com>

Sources/LeafKit/LeafSyntax/LeafTag.swift

@@ -16,7 +16,8 @@ public var defaultTags: [String: LeafTag] = [
     "contains": Contains(),
     "date": DateTag(),
     "count": Count(),
-    "comment": Comment()
+    "comment": Comment(),
+    "dumpContext": DumpContext()
 ]
 
 struct UnsafeHTML: UnsafeUnescapedLeafTag {
@@ -108,3 +109,10 @@ struct Comment: LeafTag {
         LeafData.trueNil
     }
 }
+
+struct DumpContext: LeafTag {
+    func render(_ ctx: LeafContext) throws -> LeafData {
+        try ctx.requireParameterCount(0)
+        return LeafData(.dictionary(ctx.data))
+    }
+}

Tests/LeafKitTests/TagTests.swift

@@ -176,6 +176,18 @@ class TagTests: XCTestCase {
         try XCTAssertEqual(render(template, ["now": .int(now)]), expected)
     }
 
+    func testDumpContext() throws {
+        let data: [String: LeafData] = ["value": 12345]
+        let template = """
+        dumpContext should output debug description #dumpContext
+        """
+
+        let expected = """
+        dumpContext should output debug description [value: "12345"]
+        """
+
+        try XCTAssertEqual(render(template, data), expected)
+    }
 
     func testPerformance() throws {
         let template = """