InstructionTree: Add tests for serializing scripts from Blocks

This gets a little further to verifying how we get from Blocks to actual
scripts. Parameter substitution isn't currently tested as that seems
difficult to manage without the UI.

Author: dbnicholson

tests/test_instruction_tree.gd

@@ -1,6 +1,34 @@
 extends GutTest
 ## Tests for InstructionTree
 
+var general_blocks: Dictionary
+
+
+func build_block_map(block_map: Dictionary, blocks: Array[Block]):
+	assert_eq(block_map, {})
+	for block in blocks:
+		assert_does_not_have(block_map, block.block_name, "Block name %s is duplicated" % block.block_name)
+		block_map[block.block_name] = block
+
+
+func free_block_map(block_map: Dictionary):
+	for block in block_map.values():
+		block.free()
+	block_map.clear()
+	assert_eq(block_map, {})
+
+
+func dup_node(node: Node) -> Node:
+	return node.duplicate(DUPLICATE_USE_INSTANTIATION)
+
+
+func before_each():
+	build_block_map(general_blocks, CategoryFactory.get_general_blocks())
+
+
+func after_each():
+	free_block_map(general_blocks)
+
 
 func test_single_node_text():
 	var node = InstructionTree.TreeNode.new("blah")
@@ -53,3 +81,138 @@ func test_tree_node_text():
 
 	var text: String = InstructionTree.generate_text(root, 0)
 	assert_eq(text, "root\n\tchild1\n\t\tgrandchild\n\tchild2\nsibling\n\tnephew\n")
+
+
+func test_script_no_nodes():
+	var script = InstructionTree.generate_script_from_nodes([], "Foo")
+	assert_eq(
+		script,
+		(
+			"""\
+			extends Foo
+
+			var VAR_DICT := {}
+
+			"""
+			. dedent()
+		)
+	)
+
+
+func test_script_no_entry_blocks():
+	var nodes: Array[Node] = [Node.new(), Node2D.new(), Control.new()]
+	var script = InstructionTree.generate_script_from_nodes(nodes, "Foo")
+	assert_eq(
+		script,
+		(
+			"""\
+			extends Foo
+
+			var VAR_DICT := {}
+
+			"""
+			. dedent()
+		)
+	)
+	for node in nodes:
+		node.free()
+
+
+func test_basic_script():
+	var ready_block: Block = dup_node(general_blocks["ready_block"])
+
+	var print_block: Block = dup_node(general_blocks["print"])
+	# XXX: It seems like this should substitute {text} in the statement,
+	# but it doesn't. I can't make sense of StatementBlock.
+	# print_block.param_input_strings = {"text": "this is a test"}
+	# print_block._ready()
+
+	# XXX: Why does insert_snapped_block add_child but not set snapped_block?
+	ready_block.bottom_snap.insert_snapped_block(print_block)
+	ready_block.bottom_snap.snapped_block = print_block
+	assert_true(ready_block.bottom_snap.has_snapped_block())
+	assert_eq(ready_block.bottom_snap.get_snapped_block(), print_block)
+
+	var script = InstructionTree.generate_script_from_nodes([ready_block], "Node2D")
+	assert_eq(
+		script,
+		(
+			"""\
+			extends Node2D
+
+			var VAR_DICT := {}
+
+			func _ready():
+				print({text})
+
+			"""
+			. dedent()
+		)
+	)
+
+	ready_block.free()
+
+
+func test_multiple_entry_script():
+	var ready_block: Block = dup_node(general_blocks["ready_block"])
+	var print_block: Block = dup_node(general_blocks["print"])
+	ready_block.bottom_snap.insert_snapped_block(print_block)
+	ready_block.bottom_snap.snapped_block = print_block
+
+	var ready_block_2: Block = dup_node(ready_block)
+
+	var script = InstructionTree.generate_script_from_nodes([ready_block, ready_block_2], "Node2D")
+	assert_eq(
+		script,
+		(
+			"""\
+			extends Node2D
+
+			var VAR_DICT := {}
+
+			func _ready():
+				print({text})
+
+				print({text})
+
+			"""
+			. dedent()
+		)
+	)
+
+	ready_block.free()
+	ready_block_2.free()
+
+
+func test_signal_script():
+	var area2d_blocks: Dictionary
+	build_block_map(area2d_blocks, CategoryFactory.get_inherited_blocks("Area2D"))
+	var entered_block: Block = dup_node(area2d_blocks["area2d_on_entered"])
+	var print_block: Block = dup_node(general_blocks["print"])
+	entered_block.bottom_snap.insert_snapped_block(print_block)
+	entered_block.bottom_snap.snapped_block = print_block
+
+	var script = InstructionTree.generate_script_from_nodes([entered_block], "Area2D")
+	assert_eq(
+		script,
+		(
+			"""\
+			extends Area2D
+
+			var VAR_DICT := {}
+
+
+			func _on_body_entered(_body: Node2D):
+				var body: NodePath = _body.get_path()
+
+				print({text})
+
+			func _init():
+				body_entered.connect(_on_body_entered)
+			"""
+			. dedent()
+		)
+	)
+
+	entered_block.free()
+	free_block_map(area2d_blocks)