InstructionTree: Make generation methods static

These methods don't use any state, so there's no reason to allocate an
InstructionTree object. This likely cleans some memory leaks as the
allocated objects weren't being freed in NodeBlockCanvas.

Author: dbnicholson

addons/block_code/instruction_tree/instruction_tree.gd

@@ -42,13 +42,13 @@ class IDHandler:
 		return unique_string
 
 
-func generate_text(root_node: TreeNode, start_depth: int = 0) -> String:
+static func generate_text(root_node: TreeNode, start_depth: int = 0) -> String:
 	var out = PackedStringArray()
 	generate_text_recursive(root_node, start_depth, out)
 	return "".join(out)
 
 
-func generate_text_recursive(node: TreeNode, depth: int, out: PackedStringArray):
+static func generate_text_recursive(node: TreeNode, depth: int, out: PackedStringArray):
 	if node.data != "":
 		out.append("\t".repeat(depth) + node.data + "\n")
 

addons/block_code/ui/block_canvas/node_block_canvas/node_block_canvas.gd

@@ -36,7 +36,7 @@ func generate_script_from_current_window(bsd: BlockScriptData):
 		script += _generate_script_from_entry_blocks(entry_statement, entry_blocks, init_func)
 
 	if init_func.children:
-		script += InstructionTree.new().generate_text(init_func)
+		script += InstructionTree.generate_text(init_func)
 
 	return script
 
@@ -52,9 +52,8 @@ func _generate_script_from_entry_blocks(entry_statement: String, entry_blocks: A
 		var next_block := entry_block.bottom_snap.get_snapped_block()
 
 		if next_block != null:
-			var generator: InstructionTree = InstructionTree.new()
 			var instruction_node: InstructionTree.TreeNode = next_block.get_instruction_node()
-			var to_append := generator.generate_text(instruction_node, 1)
+			var to_append := InstructionTree.generate_text(instruction_node, 1)
 			script += to_append
 			script += "\n"
 			is_empty = false

tests/test_instruction_tree.gd

@@ -1,30 +1,18 @@
 extends GutTest
 ## Tests for InstructionTree
 
-var tree: InstructionTree = null
-
-
-func before_each():
-	tree = InstructionTree.new()
-
-
-func after_each():
-	if tree != null:
-		tree.free()
-		tree = null
-
 
 func test_single_node_text():
 	var node = InstructionTree.TreeNode.new("blah")
-	var text: String = tree.generate_text(node, 0)
+	var text: String = InstructionTree.generate_text(node, 0)
 	assert_eq(text, "blah\n")
 
 
 func test_root_depth_text():
 	var node = InstructionTree.TreeNode.new("blah")
 	var text: String
 	for depth in range(5):
-		text = tree.generate_text(node, depth)
+		text = InstructionTree.generate_text(node, depth)
 		assert_eq(text, "\t".repeat(depth) + "blah\n")
 
 
@@ -34,7 +22,7 @@ func test_child_node_text():
 	var grandchild = InstructionTree.TreeNode.new("grandchild")
 	parent.add_child(child)
 	child.add_child(grandchild)
-	var text: String = tree.generate_text(parent, 0)
+	var text: String = InstructionTree.generate_text(parent, 0)
 	assert_eq(text, "parent\n\tchild\n\t\tgrandchild\n")
 
 
@@ -44,7 +32,7 @@ func test_sibling_node_text():
 	var sister = InstructionTree.TreeNode.new("sister")
 	node.next = brother
 	brother.next = sister
-	var text: String = tree.generate_text(node, 0)
+	var text: String = InstructionTree.generate_text(node, 0)
 	assert_eq(text, "node\nbrother\nsister\n")
 
 
@@ -63,5 +51,5 @@ func test_tree_node_text():
 	root.next = sibling
 	sibling.add_child(nephew)
 
-	var text: String = tree.generate_text(root, 0)
+	var text: String = InstructionTree.generate_text(root, 0)
 	assert_eq(text, "root\n\tchild1\n\t\tgrandchild\n\tchild2\nsibling\n\tnephew\n")