Add a versioned schema change deliberately

Worked example

A reset matrix separates round score, saved progress and comfort preferences. Restarting a round may clear score while retaining a mute preference, if documented. Scaffold C-STATE-SAVE — Validated inventory and checkpoint data Setup: Attach to a Node named SaveData. This is a separate file from C-SAVE and only reads fixed known scalar fields. get_checkpoint_data returns plain data, not live node references. When applying a loaded checkpoint, the assignment maps checkpoint ID to a teacher-approved safe Marker2D, never to a filename supplied by the save. ```gdscript extends Node const PATH: String = "user://seed_station_v1.json" func defaults() -> Dictionary: return {"version": 1, "seed": 0, "water": 0, "checkpoint": "start"} func _bounded_count(value: Variant) -> int: if value is int or value is float: return clampi(int(value), 0, 99) return 0 func validate(raw: Variant) -> Dictionary: var clean := defaults() if not raw is Dictionary: return clean var data: Dictionary = raw if data.get("version", 0) != 1: return clean clean["seed"] = _bounded_count(data.get("seed", 0)) clean["water"] = _bounded_count(data.get("water", 0)) var checkpoint: Variant = data.get("checkpoint", "start") if checkpoint is String and checkpoint in ["start", "greenhouse"]: clean["checkpoint"] = checkpoint return clean func save_data(raw: Dictionary) -> bool: var file := FileAccess.open(PATH, FileAccess.WRITE) if file == null: return false file.store_string(JSON.stringify(validate(raw))) file.close() return true func load_data() -> Dictionary: if not FileAccess.file_exists(PATH): return defaults() var file := FileAccess.open(PATH, FileAccess.READ) if file == null: return defaults() var text: String = file.get_as_text() file.close() var parser := JSON.new() if parser.parse(text) != OK: return defaults() return validate(parser.data) ``` Scaffold C-WORLD-DATA — Consistent pickup/bed persistence with derived inventory Setup: Attach to a separate Node named WorldData. This is the default integrated Seed Station model after the scalar-save lab. Fixed pickup IDs are s1,s2,s3,w1,w2; fixed bed IDs are b1,b2. Manager records picked IDs only after a successful pickup and planted IDs only after validating both resource costs. Inventory is derived from these IDs, so reloading cannot keep quantities while respawning already-picked rewards. On load, hide/free picked objects, mark planted beds, set the known start/greenhouse marker, then refresh HUD. Version 1 scalar labs are intentionally not migrated: report a new-game fallback. ```gdscript extends Node const PATH: String = "user://seed_station_world_v2.json" func defaults() -> Dictionary: return {"version": 2, "picked": [], "planted": [], "seed": 0, "water": 0, "checkpoint": "start"} func _ids(raw: Variant, allowed: Array) -> Array[String]: var clean: Array[String] = [] if raw is Array: for value in raw: if value is String and value in allowed and value not in clean: clean.append(value) return clean func validate(raw: Variant) -> Dictionary: var result := defaults() if not raw is Dictionary: return result var data: Dictionary = raw if data.get("version", 0) != 2: return result var picked := _ids(data.get("picked", []), ["s1", "s2", "s3", "w1", "w2"]) var planted := _ids(data.get("planted", []), ["b1", "b2"]) var seed_total: int = 0 var water_total: int = 0 for id in picked: if id.begins_with("s"): seed_total += 1 else: water_total += 1 while planted.size() > mini(seed_total, water_total): planted.pop_back() result["picked"] = picked result["planted"] = planted result["seed"] = seed_total - planted.size() result["water"] = water_total - planted.size() result["checkpoint"] = "greenhouse" if "b1" in planted else "start" return result func save_data(raw: Dictionary) -> bool: var file := FileAccess.open(PATH, FileAccess.WRITE) if file == null: return false file.store_string(JSON.stringify(validate(raw))) file.close() return true func load_data() -> Dictionary: if not FileAccess.file_exists(PATH): return defaults() var file := FileAccess.open(PATH, FileAccess.READ) if file == null: return defaults() var text: String = file.get_as_text() file.close() var parser := JSON.new() if parser.parse(text) != OK: return defaults() return validate(parser.data) ```

Validated inventory and checkpoint data

GDScript (Godot 4, not Scratch, Python, JavaScript or C#). Scaffold C-STATE-SAVE. Copy starts from this text. The desk does not run it.

Scene and node setup

Attach to a Node named SaveData. This is a separate file from C-SAVE and only reads fixed known scalar fields. get_checkpoint_data returns plain data, not live node references. When applying a loaded checkpoint, the assignment maps checkpoint ID to a teacher-approved safe Marker2D, never to a filename supplied by the save.

extends Node
const PATH: String = "user://seed_station_v1.json"
func defaults() -> Dictionary:
    return {"version": 1, "seed": 0, "water": 0, "checkpoint": "start"}
func _bounded_count(value: Variant) -> int:
    if value is int or value is float:
        return clampi(int(value), 0, 99)
    return 0
func validate(raw: Variant) -> Dictionary:
    var clean := defaults()
    if not raw is Dictionary:
        return clean
    var data: Dictionary = raw
    if data.get("version", 0) != 1:
        return clean
    clean["seed"] = _bounded_count(data.get("seed", 0))
    clean["water"] = _bounded_count(data.get("water", 0))
    var checkpoint: Variant = data.get("checkpoint", "start")
    if checkpoint is String and checkpoint in ["start", "greenhouse"]:
        clean["checkpoint"] = checkpoint
    return clean
func save_data(raw: Dictionary) -> bool:
    var file := FileAccess.open(PATH, FileAccess.WRITE)
    if file == null:
        return false
    file.store_string(JSON.stringify(validate(raw)))
    file.close()
    return true
func load_data() -> Dictionary:
    if not FileAccess.file_exists(PATH):
        return defaults()
    var file := FileAccess.open(PATH, FileAccess.READ)
    if file == null:
        return defaults()
    var text: String = file.get_as_text()
    file.close()
    var parser := JSON.new()
    if parser.parse(text) != OK:
        return defaults()
    return validate(parser.data)

Checks to run in the editor

• Missing file returns defaults.
• Negative count becomes zero; count 1000 becomes 99.
• Unknown checkpoint becomes start.
• Malformed JSON, arrays and unsupported versions return safe defaults.

Native Godot 4.7.2.stable.official.ed1daf0bf headless compile and representative node-tree/runtime tests passed; see native-qa-results.json. Visual UI, audible output, exports and website submission still need separate checks.

Consistent pickup/bed persistence with derived inventory

GDScript (Godot 4, not Scratch, Python, JavaScript or C#). Scaffold C-WORLD-DATA. Copy starts from this text. The desk does not run it.

Scene and node setup

Attach to a separate Node named WorldData. This is the default integrated Seed Station model after the scalar-save lab. Fixed pickup IDs are s1,s2,s3,w1,w2; fixed bed IDs are b1,b2. Manager records picked IDs only after a successful pickup and planted IDs only after validating both resource costs. Inventory is derived from these IDs, so reloading cannot keep quantities while respawning already-picked rewards. On load, hide/free picked objects, mark planted beds, set the known start/greenhouse marker, then refresh HUD. Version 1 scalar labs are intentionally not migrated: report a new-game fallback.

extends Node
const PATH: String = "user://seed_station_world_v2.json"
func defaults() -> Dictionary:
    return {"version": 2, "picked": [], "planted": [], "seed": 0, "water": 0, "checkpoint": "start"}
func _ids(raw: Variant, allowed: Array) -> Array[String]:
    var clean: Array[String] = []
    if raw is Array:
        for value in raw:
            if value is String and value in allowed and value not in clean:
                clean.append(value)
    return clean
func validate(raw: Variant) -> Dictionary:
    var result := defaults()
    if not raw is Dictionary:
        return result
    var data: Dictionary = raw
    if data.get("version", 0) != 2:
        return result
    var picked := _ids(data.get("picked", []), ["s1", "s2", "s3", "w1", "w2"])
    var planted := _ids(data.get("planted", []), ["b1", "b2"])
    var seed_total: int = 0
    var water_total: int = 0
    for id in picked:
        if id.begins_with("s"):
            seed_total += 1
        else:
            water_total += 1
    while planted.size() > mini(seed_total, water_total):
        planted.pop_back()
    result["picked"] = picked
    result["planted"] = planted
    result["seed"] = seed_total - planted.size()
    result["water"] = water_total - planted.size()
    result["checkpoint"] = "greenhouse" if "b1" in planted else "start"
    return result
func save_data(raw: Dictionary) -> bool:
    var file := FileAccess.open(PATH, FileAccess.WRITE)
    if file == null:
        return false
    file.store_string(JSON.stringify(validate(raw)))
    file.close()
    return true
func load_data() -> Dictionary:
    if not FileAccess.file_exists(PATH):
        return defaults()
    var file := FileAccess.open(PATH, FileAccess.READ)
    if file == null:
        return defaults()
    var text: String = file.get_as_text()
    file.close()
    var parser := JSON.new()
    if parser.parse(text) != OK:
        return defaults()
    return validate(parser.data)

Checks to run in the editor

• Picked s1,s2,w1 and planted b1 yields seed1,water0,greenhouse.
• Duplicate s1 entries do not add extra inventory.
• No collected IDs plus two planted IDs cleans to no planted beds.
• Reload removes collected pickups and restores planted-bed state through the manager.

Native Godot 4.7.2.stable.official.ed1daf0bf headless compile and representative node-tree/runtime tests passed; see native-qa-results.json. Visual UI, audible output, exports and website submission still need separate checks.

Add a versioned schema change deliberately — evidence task

1. 1. Add one validated field and document old-version behavior.
2. 2. Test old version, current version and an unsupported future version.

Deliverable. Schema change note, validator source and three-version tests.

Acceptance checks

• VGC-L117-T1. The new field has a safe default.
• VGC-L117-T2. Unsupported versions follow the documented fallback instead of crashing.

Understanding question. Why not assume a larger version number means compatible data?

Include a downloadable project ZIP with project.godot, .tscn, .gd and original asset files when code changes. A private, teacher-accessible download link to that ZIP is equivalent. Screenshots or a playthrough do not replace editable source.

If this is still shaky. If full world persistence is too large, use the documented checkpoint-only reset policy. Do not claim unsaved flags persist. Start with the first assigned task and re-run its acceptance test before adding the remaining feature.

Optional extra. Add one small validated setting using a separate save field or configuration file. Document one changed parameter, your prediction, and the observed effect; optional, not required for completion.

Turn in typed notes and a JPEG, PNG, or WebP screenshot. One https address is stored as text and is not opened, extracted, or run. An MP3, WAV, M4A, MP4, or WebM file up to 4 MB can show a demo. The demo does not replace editable source. Zip and code files are refused. If there is no private link, keep the project on the family computer and review the code in person.

• Godot step by step: nodes, scenes, GDScript, input, signals

  Free public documentation, no account. Same class help is available within the desktop editor.

  · Opening this link does not submit the lesson.
• Saving games: FileAccess and JSON

  Free public documentation, no account.

  · Opening this link does not submit the lesson.