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fakecloud_dynamodb/
state.rs

1use chrono::{DateTime, Utc};
2use parking_lot::RwLock;
3use serde::{Deserialize, Serialize};
4use serde_json::Value;
5use std::collections::{BTreeMap, HashMap};
6use std::sync::Arc;
7
8fn empty_stream_records() -> Arc<RwLock<Vec<StreamRecord>>> {
9    Arc::new(RwLock::new(Vec::new()))
10}
11
12/// Serde for `Arc<RwLock<Vec<StreamRecord>>>`: persist the inner change records
13/// so a stream consumer's un-read records survive a snapshot restart
14/// (bug-audit 2026-05-28, 4.5). The field was `#[serde(skip)]`, so table data
15/// was preserved across restart but pending stream records silently vanished.
16mod stream_records_serde {
17    use super::{Arc, RwLock, StreamRecord};
18    use serde::{Deserialize, Deserializer, Serialize, Serializer};
19
20    pub fn serialize<S: Serializer>(
21        v: &Arc<RwLock<Vec<StreamRecord>>>,
22        s: S,
23    ) -> Result<S::Ok, S::Error> {
24        v.read().serialize(s)
25    }
26
27    pub fn deserialize<'de, D: Deserializer<'de>>(
28        d: D,
29    ) -> Result<Arc<RwLock<Vec<StreamRecord>>>, D::Error> {
30        let records = Vec::<StreamRecord>::deserialize(d)?;
31        // Raise the in-memory sequence-number floor above every persisted
32        // record so newly-minted numbers cannot collide with them after a
33        // restart, even if the wall-clock seed went backwards (4.4 / Cubic).
34        for r in &records {
35            crate::streams::observe_stream_sequence(&r.dynamodb.sequence_number);
36        }
37        Ok(Arc::new(RwLock::new(records)))
38    }
39}
40
41/// A single DynamoDB attribute value (tagged union matching the AWS wire format).
42/// AWS sends attribute values as `{"S": "hello"}`, `{"N": "42"}`, etc.
43pub type AttributeValue = Value;
44
45/// Extract the "typed" inner value for comparison purposes.
46/// Returns (type_tag, inner_value) e.g. ("S", "hello") or ("N", "42").
47pub fn attribute_type_and_value(av: &Value) -> Option<(&str, &Value)> {
48    let obj = av.as_object()?;
49    if obj.len() != 1 {
50        return None;
51    }
52    let (k, v) = obj.iter().next()?;
53    Some((k.as_str(), v))
54}
55
56#[derive(Debug, Clone, Serialize, Deserialize)]
57pub struct KeySchemaElement {
58    pub attribute_name: String,
59    pub key_type: String, // HASH or RANGE
60}
61
62#[derive(Debug, Clone, Serialize, Deserialize)]
63pub struct AttributeDefinition {
64    pub attribute_name: String,
65    pub attribute_type: String, // S, N, B
66}
67
68#[derive(Debug, Clone, Serialize, Deserialize)]
69pub struct ProvisionedThroughput {
70    pub read_capacity_units: i64,
71    pub write_capacity_units: i64,
72}
73
74/// On-demand capacity caps for PAY_PER_REQUEST tables and GSIs. Real AWS
75/// accepts both fields independently; `-1` (the AWS sentinel for "no cap")
76/// is the default and is what `DescribeTable` returns when the caller never
77/// set a value — the Terraform provider asserts on that exact value.
78#[derive(Debug, Clone, Serialize, Deserialize)]
79pub struct OnDemandThroughput {
80    pub max_read_request_units: i64,
81    pub max_write_request_units: i64,
82}
83
84#[derive(Debug, Clone, Serialize, Deserialize)]
85pub struct GlobalSecondaryIndex {
86    pub index_name: String,
87    pub key_schema: Vec<KeySchemaElement>,
88    pub projection: Projection,
89    pub provisioned_throughput: Option<ProvisionedThroughput>,
90    pub on_demand_throughput: Option<OnDemandThroughput>,
91}
92
93#[derive(Debug, Clone, Serialize, Deserialize)]
94pub struct LocalSecondaryIndex {
95    pub index_name: String,
96    pub key_schema: Vec<KeySchemaElement>,
97    pub projection: Projection,
98}
99
100#[derive(Debug, Clone, Serialize, Deserialize)]
101pub struct Projection {
102    pub projection_type: String, // ALL, KEYS_ONLY, INCLUDE
103    pub non_key_attributes: Vec<String>,
104}
105
106#[derive(Debug, Clone, Serialize, Deserialize)]
107pub struct DynamoTable {
108    pub name: String,
109    pub arn: String,
110    pub table_id: String,
111    pub key_schema: Vec<KeySchemaElement>,
112    pub attribute_definitions: Vec<AttributeDefinition>,
113    pub provisioned_throughput: ProvisionedThroughput,
114    pub items: Vec<HashMap<String, AttributeValue>>,
115    pub gsi: Vec<GlobalSecondaryIndex>,
116    pub lsi: Vec<LocalSecondaryIndex>,
117    pub tags: BTreeMap<String, String>,
118    pub created_at: DateTime<Utc>,
119    pub status: String,
120    pub item_count: i64,
121    pub size_bytes: i64,
122    pub billing_mode: String, // PROVISIONED or PAY_PER_REQUEST
123    pub ttl_attribute: Option<String>,
124    pub ttl_enabled: bool,
125    pub resource_policy: Option<String>,
126    /// PITR enabled
127    pub pitr_enabled: bool,
128    /// Kinesis streaming destinations: stream_arn -> status
129    pub kinesis_destinations: Vec<KinesisDestination>,
130    /// Contributor insights status
131    pub contributor_insights_status: String,
132    /// Contributor insights: partition key access counters (key_value_string -> count)
133    pub contributor_insights_counters: BTreeMap<String, u64>,
134    /// DynamoDB Streams configuration
135    pub stream_enabled: bool,
136    pub stream_view_type: Option<String>, // KEYS_ONLY, NEW_IMAGE, OLD_IMAGE, NEW_AND_OLD_IMAGES
137    pub stream_arn: Option<String>,
138    /// Stream records (retained for 24 hours). Not persisted: stream
139    /// records are ephemeral and would be garbage anyway across restarts.
140    #[serde(with = "stream_records_serde", default = "empty_stream_records")]
141    pub stream_records: Arc<RwLock<Vec<StreamRecord>>>,
142    /// Server-side encryption type: AES256 (owned) or KMS
143    pub sse_type: Option<String>,
144    /// KMS key ARN for SSE (only when sse_type is KMS)
145    pub sse_kms_key_arn: Option<String>,
146    /// Deletion protection: when true, DeleteTable is rejected with
147    /// `ResourceInUseException`. Defaults to false. Returned on every
148    /// `DescribeTable` and toggleable via `UpdateTable`.
149    pub deletion_protection_enabled: bool,
150    /// Table-level on-demand throughput caps. Only meaningful for
151    /// PAY_PER_REQUEST tables, but real AWS echoes the field on every
152    /// DescribeTable once set.
153    pub on_demand_throughput: Option<OnDemandThroughput>,
154}
155
156#[derive(Debug, Clone, Serialize, Deserialize)]
157pub struct StreamRecord {
158    pub event_id: String,
159    pub event_name: String, // INSERT, MODIFY, REMOVE
160    pub event_version: String,
161    pub event_source: String,
162    pub aws_region: String,
163    pub dynamodb: DynamoDbStreamRecord,
164    pub event_source_arn: String,
165    pub timestamp: DateTime<Utc>,
166}
167
168#[derive(Debug, Clone, Serialize, Deserialize)]
169pub struct DynamoDbStreamRecord {
170    pub keys: HashMap<String, AttributeValue>,
171    pub new_image: Option<HashMap<String, AttributeValue>>,
172    pub old_image: Option<HashMap<String, AttributeValue>>,
173    pub sequence_number: String,
174    pub size_bytes: i64,
175    pub stream_view_type: String,
176}
177
178#[derive(Debug, Clone, Serialize, Deserialize)]
179pub struct KinesisDestination {
180    pub stream_arn: String,
181    pub destination_status: String,
182    pub approximate_creation_date_time_precision: String,
183}
184
185#[derive(Debug, Clone, Serialize, Deserialize)]
186pub struct BackupDescription {
187    pub backup_arn: String,
188    pub backup_name: String,
189    pub table_name: String,
190    pub table_arn: String,
191    pub backup_status: String,
192    pub backup_type: String,
193    pub backup_creation_date: DateTime<Utc>,
194    pub key_schema: Vec<KeySchemaElement>,
195    pub attribute_definitions: Vec<AttributeDefinition>,
196    pub provisioned_throughput: ProvisionedThroughput,
197    pub billing_mode: String,
198    pub item_count: i64,
199    pub size_bytes: i64,
200    /// Snapshot of the table items at backup creation time.
201    pub items: Vec<HashMap<String, AttributeValue>>,
202    /// Real DDB persists GSI/LSI/tags/TTL/SSE/Stream into the backup
203    /// payload so RestoreTableFromBackup brings the full table back
204    /// up. Older snapshots may not have these fields, so all default
205    /// to empty/false via serde.
206    #[serde(default)]
207    pub gsi: Vec<GlobalSecondaryIndex>,
208    #[serde(default)]
209    pub lsi: Vec<LocalSecondaryIndex>,
210    #[serde(default)]
211    pub tags: BTreeMap<String, String>,
212    #[serde(default)]
213    pub ttl_attribute: Option<String>,
214    #[serde(default)]
215    pub ttl_enabled: bool,
216    #[serde(default)]
217    pub sse_type: Option<String>,
218    #[serde(default)]
219    pub sse_kms_key_arn: Option<String>,
220    #[serde(default)]
221    pub stream_enabled: bool,
222    #[serde(default)]
223    pub stream_view_type: Option<String>,
224}
225
226#[derive(Debug, Clone, Serialize, Deserialize)]
227pub struct GlobalTableDescription {
228    pub global_table_name: String,
229    pub global_table_arn: String,
230    pub global_table_status: String,
231    pub creation_date: DateTime<Utc>,
232    pub replication_group: Vec<ReplicaDescription>,
233    /// Billing mode applied across all replicas via
234    /// `UpdateGlobalTableSettings` (`PROVISIONED` / `PAY_PER_REQUEST`).
235    /// Defaults to PROVISIONED to match real DynamoDB global-table v1.
236    #[serde(default = "default_global_billing_mode")]
237    pub billing_mode: String,
238    /// Global provisioned write capacity applied across all replicas via
239    /// `UpdateGlobalTableSettings`. `None` under PAY_PER_REQUEST.
240    #[serde(default)]
241    pub provisioned_write_capacity_units: Option<i64>,
242}
243
244fn default_global_billing_mode() -> String {
245    "PROVISIONED".to_string()
246}
247
248#[derive(Debug, Clone, Serialize, Deserialize)]
249pub struct ReplicaDescription {
250    pub region_name: String,
251    pub replica_status: String,
252    /// Per-replica provisioned-read-capacity autoscaling settings, as supplied
253    /// via `UpdateTableReplicaAutoScaling`. Round-tripped through
254    /// `DescribeTableReplicaAutoScaling` as `AutoScalingSettingsDescription`.
255    #[serde(default)]
256    pub read_capacity_auto_scaling: Option<serde_json::Value>,
257    /// Per-replica provisioned-write-capacity autoscaling settings.
258    #[serde(default)]
259    pub write_capacity_auto_scaling: Option<serde_json::Value>,
260    /// Per-replica provisioned read capacity supplied via
261    /// `UpdateGlobalTableSettings` ReplicaSettingsUpdate.
262    #[serde(default)]
263    pub read_capacity_units: Option<i64>,
264}
265
266#[derive(Debug, Clone, Serialize, Deserialize)]
267pub struct ExportDescription {
268    pub export_arn: String,
269    pub export_status: String,
270    pub table_arn: String,
271    pub s3_bucket: String,
272    pub s3_prefix: Option<String>,
273    pub export_format: String,
274    pub start_time: DateTime<Utc>,
275    pub end_time: DateTime<Utc>,
276    pub export_time: DateTime<Utc>,
277    pub item_count: i64,
278    pub billed_size_bytes: i64,
279}
280
281#[derive(Debug, Clone, Serialize, Deserialize)]
282pub struct ImportDescription {
283    pub import_arn: String,
284    pub import_status: String,
285    pub table_arn: String,
286    pub table_name: String,
287    pub s3_bucket_source: String,
288    pub input_format: String,
289    pub start_time: DateTime<Utc>,
290    pub end_time: DateTime<Utc>,
291    pub processed_item_count: i64,
292    pub processed_size_bytes: i64,
293}
294
295impl DynamoTable {
296    /// Get the hash key attribute name from the key schema.
297    pub fn hash_key_name(&self) -> &str {
298        self.key_schema
299            .iter()
300            .find(|k| k.key_type == "HASH")
301            .map(|k| k.attribute_name.as_str())
302            .unwrap_or("")
303    }
304
305    /// Get the range key attribute name from the key schema (if any).
306    pub fn range_key_name(&self) -> Option<&str> {
307        self.key_schema
308            .iter()
309            .find(|k| k.key_type == "RANGE")
310            .map(|k| k.attribute_name.as_str())
311    }
312
313    /// Find an item index by its primary key.
314    pub fn find_item_index(&self, key: &HashMap<String, AttributeValue>) -> Option<usize> {
315        let hash_key = self.hash_key_name();
316        let range_key = self.range_key_name();
317
318        self.items.iter().position(|item| {
319            let hash_match = match (item.get(hash_key), key.get(hash_key)) {
320                (Some(a), Some(b)) => a == b,
321                _ => false,
322            };
323            if !hash_match {
324                return false;
325            }
326            match range_key {
327                Some(rk) => match (item.get(rk), key.get(rk)) {
328                    (Some(a), Some(b)) => a == b,
329                    (None, None) => true,
330                    _ => false,
331                },
332                None => true,
333            }
334        })
335    }
336
337    /// Estimate item size in bytes (rough approximation).
338    fn estimate_item_size(item: &HashMap<String, AttributeValue>) -> i64 {
339        let mut size: i64 = 0;
340        for (k, v) in item {
341            size += k.len() as i64;
342            size += Self::estimate_value_size(v);
343        }
344        size
345    }
346
347    fn estimate_value_size(v: &Value) -> i64 {
348        match v {
349            Value::Object(obj) => {
350                if let Some(s) = obj.get("S").and_then(|v| v.as_str()) {
351                    s.len() as i64
352                } else if let Some(n) = obj.get("N").and_then(|v| v.as_str()) {
353                    n.len() as i64
354                } else if obj.contains_key("BOOL") || obj.contains_key("NULL") {
355                    1
356                } else if let Some(l) = obj.get("L").and_then(|v| v.as_array()) {
357                    3 + l.iter().map(Self::estimate_value_size).sum::<i64>()
358                } else if let Some(m) = obj.get("M").and_then(|v| v.as_object()) {
359                    3 + m
360                        .iter()
361                        .map(|(k, v)| k.len() as i64 + Self::estimate_value_size(v))
362                        .sum::<i64>()
363                } else if let Some(ss) = obj.get("SS").and_then(|v| v.as_array()) {
364                    ss.iter()
365                        .filter_map(|v| v.as_str())
366                        .map(|s| s.len() as i64)
367                        .sum()
368                } else if let Some(ns) = obj.get("NS").and_then(|v| v.as_array()) {
369                    ns.iter()
370                        .filter_map(|v| v.as_str())
371                        .map(|s| s.len() as i64)
372                        .sum()
373                } else if let Some(b) = obj.get("B").and_then(|v| v.as_str()) {
374                    // Base64-encoded binary
375                    (b.len() as i64 * 3) / 4
376                } else {
377                    v.to_string().len() as i64
378                }
379            }
380            _ => v.to_string().len() as i64,
381        }
382    }
383
384    /// Record a partition key access for contributor insights.
385    /// Only records if contributor insights is enabled.
386    pub fn record_key_access(&mut self, key: &HashMap<String, AttributeValue>) {
387        if self.contributor_insights_status != "ENABLED" {
388            return;
389        }
390        let hash_key = self.hash_key_name().to_string();
391        if let Some(pk_value) = key.get(&hash_key) {
392            let key_str = pk_value.to_string();
393            *self
394                .contributor_insights_counters
395                .entry(key_str)
396                .or_insert(0) += 1;
397        }
398    }
399
400    /// Record a partition key access from a full item (extracts the key first).
401    pub fn record_item_access(&mut self, item: &HashMap<String, AttributeValue>) {
402        if self.contributor_insights_status != "ENABLED" {
403            return;
404        }
405        let hash_key = self.hash_key_name().to_string();
406        if let Some(pk_value) = item.get(&hash_key) {
407            let key_str = pk_value.to_string();
408            *self
409                .contributor_insights_counters
410                .entry(key_str)
411                .or_insert(0) += 1;
412        }
413    }
414
415    /// Get top N contributors sorted by access count (descending).
416    pub fn top_contributors(&self, n: usize) -> Vec<(&str, u64)> {
417        let mut entries: Vec<(&str, u64)> = self
418            .contributor_insights_counters
419            .iter()
420            .map(|(k, &v)| (k.as_str(), v))
421            .collect();
422        entries.sort_by_key(|e| std::cmp::Reverse(e.1));
423        entries.truncate(n);
424        entries
425    }
426
427    /// Recalculate item_count and size_bytes from the items vec.
428    pub fn recalculate_stats(&mut self) {
429        self.item_count = self.items.len() as i64;
430        self.size_bytes = self.items.iter().map(Self::estimate_item_size).sum::<i64>();
431    }
432}
433
434#[derive(Debug, Clone, Serialize, Deserialize)]
435pub struct DynamoDbState {
436    pub account_id: String,
437    pub region: String,
438    pub tables: BTreeMap<String, DynamoTable>,
439    pub backups: BTreeMap<String, BackupDescription>,
440    pub global_tables: BTreeMap<String, GlobalTableDescription>,
441    pub exports: BTreeMap<String, ExportDescription>,
442    pub imports: BTreeMap<String, ImportDescription>,
443}
444
445/// On-disk snapshot envelope. The payload is the full [`DynamoDbState`];
446/// `schema_version` lets us evolve the format without accidentally loading
447/// an incompatible dump on upgrade.
448#[derive(Debug, Clone, Serialize, Deserialize)]
449pub struct DynamoDbSnapshot {
450    pub schema_version: u32,
451    /// v2+: multi-account state.
452    #[serde(default)]
453    pub accounts: Option<fakecloud_core::multi_account::MultiAccountState<DynamoDbState>>,
454    /// v1 compat: single-account state.
455    #[serde(default)]
456    pub state: Option<DynamoDbState>,
457}
458
459pub const DYNAMODB_SNAPSHOT_SCHEMA_VERSION: u32 = 2;
460
461impl DynamoDbState {
462    pub fn new(account_id: &str, region: &str) -> Self {
463        Self {
464            account_id: account_id.to_string(),
465            region: region.to_string(),
466            tables: BTreeMap::new(),
467            backups: BTreeMap::new(),
468            global_tables: BTreeMap::new(),
469            exports: BTreeMap::new(),
470            imports: BTreeMap::new(),
471        }
472    }
473
474    pub fn reset(&mut self) {
475        self.tables.clear();
476        self.backups.clear();
477        self.global_tables.clear();
478        self.exports.clear();
479        self.imports.clear();
480    }
481}
482
483impl fakecloud_core::multi_account::AccountState for DynamoDbState {
484    fn new_for_account(account_id: &str, region: &str, _endpoint: &str) -> Self {
485        Self::new(account_id, region)
486    }
487}
488
489pub type SharedDynamoDbState =
490    Arc<RwLock<fakecloud_core::multi_account::MultiAccountState<DynamoDbState>>>;
491
492#[cfg(test)]
493mod tests {
494    use super::*;
495    use serde_json::json;
496
497    #[test]
498    fn attribute_type_and_value_valid() {
499        let v = json!({"S": "hi"});
500        let (ty, val) = attribute_type_and_value(&v).unwrap();
501        assert_eq!(ty, "S");
502        assert_eq!(val, &json!("hi"));
503    }
504
505    #[test]
506    fn attribute_type_and_value_empty_returns_none() {
507        let v = json!({});
508        assert!(attribute_type_and_value(&v).is_none());
509    }
510
511    #[test]
512    fn attribute_type_and_value_multiple_entries_returns_none() {
513        let v = json!({"S": "hi", "N": "1"});
514        assert!(attribute_type_and_value(&v).is_none());
515    }
516
517    #[test]
518    fn attribute_type_and_value_non_object_returns_none() {
519        let v = json!("not-object");
520        assert!(attribute_type_and_value(&v).is_none());
521    }
522
523    #[test]
524    fn account_state_trait_impl() {
525        use fakecloud_core::multi_account::AccountState;
526        let state = DynamoDbState::new_for_account("123", "us-east-1", "");
527        assert_eq!(state.account_id, "123");
528        assert_eq!(state.region, "us-east-1");
529    }
530
531    #[test]
532    fn new_and_reset() {
533        let state = DynamoDbState::new("123", "us-east-1");
534        assert!(state.tables.is_empty());
535    }
536
537    fn table_with_hash_key(hash: &str) -> DynamoTable {
538        DynamoTable {
539            name: "t".to_string(),
540            arn: "arn:aws:dynamodb:us-east-1:123:table/t".to_string(),
541            table_id: "id".to_string(),
542            key_schema: vec![KeySchemaElement {
543                attribute_name: hash.to_string(),
544                key_type: "HASH".to_string(),
545            }],
546            attribute_definitions: vec![],
547            provisioned_throughput: ProvisionedThroughput {
548                read_capacity_units: 1,
549                write_capacity_units: 1,
550            },
551            items: Vec::new(),
552            gsi: Vec::new(),
553            lsi: Vec::new(),
554            tags: BTreeMap::new(),
555            created_at: Utc::now(),
556            status: "ACTIVE".to_string(),
557            item_count: 0,
558            size_bytes: 0,
559            billing_mode: "PROVISIONED".to_string(),
560            ttl_attribute: None,
561            ttl_enabled: false,
562            resource_policy: None,
563            pitr_enabled: false,
564            kinesis_destinations: Vec::new(),
565            contributor_insights_status: "DISABLED".to_string(),
566            contributor_insights_counters: BTreeMap::new(),
567            stream_enabled: false,
568            stream_view_type: None,
569            stream_arn: None,
570            stream_records: empty_stream_records(),
571            sse_type: None,
572            sse_kms_key_arn: None,
573            deletion_protection_enabled: false,
574            on_demand_throughput: None,
575        }
576    }
577
578    #[test]
579    fn hash_key_name_extracts_from_schema() {
580        let t = table_with_hash_key("pk");
581        assert_eq!(t.hash_key_name(), "pk");
582    }
583
584    #[test]
585    fn hash_key_name_empty_when_no_hash_schema() {
586        let mut t = table_with_hash_key("pk");
587        t.key_schema.clear();
588        assert_eq!(t.hash_key_name(), "");
589    }
590
591    #[test]
592    fn record_key_access_noop_when_disabled() {
593        let mut t = table_with_hash_key("pk");
594        let mut key = HashMap::new();
595        key.insert("pk".to_string(), json!({"S": "a"}));
596        t.record_key_access(&key);
597        assert!(t.contributor_insights_counters.is_empty());
598    }
599
600    #[test]
601    fn record_key_access_increments_when_enabled() {
602        let mut t = table_with_hash_key("pk");
603        t.contributor_insights_status = "ENABLED".to_string();
604        let mut key = HashMap::new();
605        key.insert("pk".to_string(), json!({"S": "a"}));
606        t.record_key_access(&key);
607        t.record_key_access(&key);
608        assert_eq!(t.contributor_insights_counters.values().sum::<u64>(), 2);
609    }
610
611    #[test]
612    fn record_item_access_uses_hash_key_from_item() {
613        let mut t = table_with_hash_key("pk");
614        t.contributor_insights_status = "ENABLED".to_string();
615        let mut item = HashMap::new();
616        item.insert("pk".to_string(), json!({"S": "user-1"}));
617        item.insert("other".to_string(), json!({"N": "42"}));
618        t.record_item_access(&item);
619        assert_eq!(t.contributor_insights_counters.values().sum::<u64>(), 1);
620    }
621
622    #[test]
623    fn top_contributors_returns_sorted() {
624        let mut t = table_with_hash_key("pk");
625        t.contributor_insights_counters.insert("a".to_string(), 3);
626        t.contributor_insights_counters.insert("b".to_string(), 10);
627        t.contributor_insights_counters.insert("c".to_string(), 1);
628        let top = t.top_contributors(2);
629        assert_eq!(top.len(), 2);
630        assert_eq!(top[0], ("b", 10));
631        assert_eq!(top[1], ("a", 3));
632    }
633
634    #[test]
635    fn recalculate_stats_matches_items() {
636        let mut t = table_with_hash_key("pk");
637        let mut item1 = HashMap::new();
638        item1.insert("pk".to_string(), json!({"S": "hello"}));
639        let mut item2 = HashMap::new();
640        item2.insert("pk".to_string(), json!({"N": "42"}));
641        item2.insert("flag".to_string(), json!({"BOOL": true}));
642        t.items.push(item1);
643        t.items.push(item2);
644        t.recalculate_stats();
645        assert_eq!(t.item_count, 2);
646        assert!(t.size_bytes > 0);
647    }
648
649    #[test]
650    fn estimate_value_size_covers_all_types() {
651        let s = DynamoTable::estimate_value_size(&json!({"S": "abc"}));
652        assert_eq!(s, 3);
653        let n = DynamoTable::estimate_value_size(&json!({"N": "42"}));
654        assert_eq!(n, 2);
655        let b = DynamoTable::estimate_value_size(&json!({"BOOL": true}));
656        assert_eq!(b, 1);
657        let null = DynamoTable::estimate_value_size(&json!({"NULL": true}));
658        assert_eq!(null, 1);
659        let l = DynamoTable::estimate_value_size(&json!({"L": [{"S": "x"}, {"S": "yy"}]}));
660        assert_eq!(l, 6);
661        let m = DynamoTable::estimate_value_size(&json!({"M": {"key": {"S": "v"}}}));
662        assert_eq!(m, 7);
663        let ss = DynamoTable::estimate_value_size(&json!({"SS": ["ab", "cde"]}));
664        assert_eq!(ss, 5);
665        let ns = DynamoTable::estimate_value_size(&json!({"NS": ["12", "345"]}));
666        assert_eq!(ns, 5);
667        let bin = DynamoTable::estimate_value_size(&json!({"B": "AAAAAAAA"}));
668        assert_eq!(bin, 6);
669    }
670}