fix: use indexmap, not hashmap (#709)

Will solve stac-utils/rustac-py#85 once this
propogates to **rustac-py**.

Author: gadomski

Cargo.toml

@@ -48,6 +48,7 @@ geo-types = "0.7.15"
 geoarrow = "0.4.0-beta.4"
 geojson = "0.24.1"
 http = "1.1"
+indexmap = { version = "2.9.0", features = ["serde"] }
 jsonschema = { version = "0.30.0", default-features = false }
 libduckdb-sys = "1.2.1"
 log = "0.4.25"

crates/api/Cargo.toml

@@ -26,18 +26,19 @@ async-stream = { workspace = true, optional = true }
 chrono.workspace = true
 cql2.workspace = true
 futures = { workspace = true, optional = true }
-http = { workspace = true, optional = true }
-reqwest = { workspace = true, features = ["json"], optional = true }
 geo = { workspace = true, optional = true }
 geojson.workspace = true
+http = { workspace = true, optional = true }
+indexmap.workspace = true
+reqwest = { workspace = true, features = ["json"], optional = true }
 serde.workspace = true
 serde_json.workspace = true
 serde_urlencoded.workspace = true
-stac.workspace = true
 stac-derive.workspace = true
+stac.workspace = true
 thiserror.workspace = true
-tracing.workspace = true
 tokio = { workspace = true, optional = true }
+tracing.workspace = true
 url.workspace = true
 
 [dev-dependencies]

crates/api/src/items.rs

@@ -1,9 +1,9 @@
 use crate::{Error, Fields, Filter, Result, Search, Sortby};
 use chrono::{DateTime, FixedOffset};
+use indexmap::IndexMap;
 use serde::{Deserialize, Serialize};
 use serde_json::{Map, Value};
 use stac::{Bbox, Item};
-use std::collections::HashMap;
 
 /// Parameters for the items endpoint from STAC API - Features.
 #[derive(Clone, Default, Debug, Serialize, Deserialize)]
@@ -97,7 +97,7 @@ pub struct GetItems {
 
     /// Additional fields.
     #[serde(flatten)]
-    pub additional_fields: HashMap<String, String>,
+    pub additional_fields: IndexMap<String, String>,
 }
 
 impl Items {
@@ -423,12 +423,12 @@ fn maybe_parse_from_rfc3339(s: &str) -> Result<Option<DateTime<FixedOffset>>> {
 mod tests {
     use super::{GetItems, Items};
     use crate::{Fields, Filter, Sortby, sort::Direction};
+    use indexmap::IndexMap;
     use serde_json::{Map, Value, json};
-    use std::collections::HashMap;
 
     #[test]
     fn get_items_try_from_items() {
-        let mut additional_fields = HashMap::new();
+        let mut additional_fields = IndexMap::new();
         let _ = additional_fields.insert("token".to_string(), "foobar".to_string());
 
         let get_items = GetItems {

crates/core/Cargo.toml

@@ -47,6 +47,7 @@ geo = { workspace = true, optional = true }
 geo-types = { workspace = true, optional = true }
 geoarrow = { workspace = true, optional = true }
 geojson.workspace = true
+indexmap.workspace = true
 jsonschema = { workspace = true, optional = true, features = ["resolve-http"] }
 log.workspace = true
 mime.workspace = true

crates/core/src/asset.rs

@@ -1,8 +1,8 @@
 use crate::{Band, DataType, Statistics};
+use indexmap::IndexMap;
 use serde::{Deserialize, Serialize};
 use serde_json::{Map, Value};
 use stac_derive::Fields;
-use std::collections::HashMap;
 
 /// An Asset is an object that contains a URI to data associated with the [Item](crate::Item) that can be downloaded or streamed.
 #[derive(Debug, Serialize, Deserialize, PartialEq, Clone, Fields)]
@@ -98,7 +98,7 @@ pub trait Assets {
     /// let item: Item = stac::read("examples/simple-item.json").unwrap();
     /// assert!(!item.assets().is_empty());
     /// ```
-    fn assets(&self) -> &HashMap<String, Asset>;
+    fn assets(&self) -> &IndexMap<String, Asset>;
 
     /// Returns a mut reference to this object's assets.
     ///
@@ -111,7 +111,7 @@ pub trait Assets {
     /// let mut item: Item = stac::read("examples/simple-item.json").unwrap();
     /// item.assets_mut().insert("foo".to_string(), Asset::new("./asset.tif"));
     /// ```
-    fn assets_mut(&mut self) -> &mut HashMap<String, Asset>;
+    fn assets_mut(&mut self) -> &mut IndexMap<String, Asset>;
 }
 
 impl Asset {

crates/core/src/collection.rs

@@ -3,10 +3,10 @@ use crate::{
     SelfHref, Version,
 };
 use chrono::{DateTime, Utc};
+use indexmap::IndexMap;
 use serde::{Deserialize, Deserializer, Serialize};
 use serde_json::{Map, Value};
 use stac_derive::{Fields, Links, SelfHref};
-use std::collections::HashMap;
 
 const DEFAULT_LICENSE: &str = "other";
 
@@ -107,12 +107,12 @@ pub struct Collection {
     pub links: Vec<Link>,
 
     /// Dictionary of asset objects that can be downloaded, each with a unique key.
-    #[serde(skip_serializing_if = "HashMap::is_empty", default)]
-    pub assets: HashMap<String, Asset>,
+    #[serde(skip_serializing_if = "IndexMap::is_empty", default)]
+    pub assets: IndexMap<String, Asset>,
 
     /// A dictionary of assets that can be found in member Items.
-    #[serde(skip_serializing_if = "HashMap::is_empty", default)]
-    pub item_assets: HashMap<String, ItemAsset>,
+    #[serde(skip_serializing_if = "IndexMap::is_empty", default)]
+    pub item_assets: IndexMap<String, ItemAsset>,
 
     /// Additional fields not part of the `Collection` specification.
     #[serde(flatten)]
@@ -208,8 +208,8 @@ impl Collection {
             extent: Extent::default(),
             summaries: None,
             links: Vec::new(),
-            assets: HashMap::new(),
-            item_assets: HashMap::new(),
+            assets: IndexMap::new(),
+            item_assets: IndexMap::new(),
             additional_fields: Map::new(),
             self_href: None,
         }
@@ -380,10 +380,10 @@ impl Default for TemporalExtent {
 }
 
 impl Assets for Collection {
-    fn assets(&self) -> &HashMap<String, Asset> {
+    fn assets(&self) -> &IndexMap<String, Asset> {
         &self.assets
     }
-    fn assets_mut(&mut self) -> &mut HashMap<String, Asset> {
+    fn assets_mut(&mut self) -> &mut IndexMap<String, Asset> {
         &mut self.assets
     }
 }

crates/core/src/item.rs

@@ -3,10 +3,11 @@
 use crate::{Asset, Assets, Bbox, Error, Fields, Href, Link, Result, STAC_VERSION, Version};
 use chrono::{DateTime, FixedOffset, NaiveDateTime, Utc};
 use geojson::{Feature, Geometry, feature::Id};
+use indexmap::IndexMap;
 use serde::{Deserialize, Deserializer, Serialize};
 use serde_json::{Map, Value};
 use stac_derive::{Links, Migrate, SelfHref};
-use std::{collections::HashMap, path::Path};
+use std::path::Path;
 use url::Url;
 
 const TOP_LEVEL_ATTRIBUTES: [&str; 8] = [
@@ -98,7 +99,7 @@ pub struct Item {
 
     /// Dictionary of asset objects that can be downloaded, each with a unique key.
     #[serde(default)]
-    pub assets: HashMap<String, Asset>,
+    pub assets: IndexMap<String, Asset>,
 
     /// The `id` of the STAC [Collection](crate::Collection) this `Item`
     /// references to.
@@ -157,7 +158,7 @@ pub struct FlatItem {
     pub links: Vec<Link>,
 
     /// Dictionary of asset objects that can be downloaded, each with a unique key.
-    pub assets: HashMap<String, Asset>,
+    pub assets: IndexMap<String, Asset>,
 
     /// The ID of the collection this Item is a part of.
     pub collection: Option<String>,
@@ -246,7 +247,7 @@ pub struct Properties {
 pub struct Builder {
     id: String,
     canonicalize_paths: bool,
-    assets: HashMap<String, Asset>,
+    assets: IndexMap<String, Asset>,
 }
 
 impl Builder {
@@ -262,7 +263,7 @@ impl Builder {
         Builder {
             id: id.to_string(),
             canonicalize_paths: true,
-            assets: HashMap::new(),
+            assets: IndexMap::new(),
         }
     }
 
@@ -357,7 +358,7 @@ impl Item {
             bbox: None,
             properties: Properties::default(),
             links: Vec::new(),
-            assets: HashMap::new(),
+            assets: IndexMap::new(),
             collection: None,
             additional_fields: Map::new(),
             self_href: None,
@@ -592,10 +593,10 @@ impl Item {
 }
 
 impl Assets for Item {
-    fn assets(&self) -> &HashMap<String, Asset> {
+    fn assets(&self) -> &IndexMap<String, Asset> {
         &self.assets
     }
-    fn assets_mut(&mut self) -> &mut HashMap<String, Asset> {
+    fn assets_mut(&mut self) -> &mut IndexMap<String, Asset> {
         &mut self.assets
     }
 }

crates/extensions/Cargo.toml

@@ -13,6 +13,7 @@ rust-version.workspace = true
 
 [dependencies]
 geojson.workspace = true
-stac.workspace = true
+indexmap.workspace = true
 serde.workspace = true
 serde_json.workspace = true
+stac.workspace = true

crates/extensions/src/authentication.rs

@@ -4,17 +4,17 @@
 //! security spec](https://swagger.io/docs/specification/authentication/).
 
 use crate::Extension;
+use indexmap::IndexMap;
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
-use std::collections::HashMap;
 
 /// The authentication extension fields.
 #[derive(Debug, Serialize, Deserialize)]
 pub struct Authentication {
     /// A property that contains all of the [scheme definitions](Scheme) used by
     /// [Assets](stac::Asset) and [Links](stac::Link) in the STAC [Item](crate::Item) or [Collection](crate::Collection).
-    #[serde(default, skip_serializing_if = "HashMap::is_empty")]
-    pub schemes: HashMap<String, Scheme>,
+    #[serde(default, skip_serializing_if = "IndexMap::is_empty")]
+    pub schemes: IndexMap<String, Scheme>,
 
     /// A property that specifies which schemes may be used to access an [Asset](stac::Asset)
     /// or [Link](stac::Link).
@@ -60,8 +60,8 @@ pub struct Scheme {
     /// OAuth flows: `authorizationCode` | `implicit` | `password` |
     /// `clientCredentials`.  The OAuth2 Flow Object applies for oauth2, the
     /// Signed URL Object applies to signedUrl.
-    #[serde(skip_serializing_if = "HashMap::is_empty", default)]
-    pub flows: HashMap<String, Flow>,
+    #[serde(skip_serializing_if = "IndexMap::is_empty", default)]
+    pub flows: IndexMap<String, Flow>,
 
     /// OpenID Connect URL to discover OpenID configuration values.
     ///
@@ -94,7 +94,7 @@ pub enum Flow {
         /// The available scopes for the authentication scheme.
         ///
         /// A map between the scope name and a short description for it. The map MAY be empty.
-        scopes: HashMap<String, String>,
+        scopes: IndexMap<String, String>,
 
         /// The URL to be used for obtaining refresh tokens.
         ///
@@ -115,8 +115,8 @@ pub enum Flow {
         authorization_api: Option<String>,
 
         /// Parameter definition for requests to the authorizationApi
-        #[serde(skip_serializing_if = "HashMap::is_empty")]
-        parameters: HashMap<String, Parameter>,
+        #[serde(skip_serializing_if = "IndexMap::is_empty")]
+        parameters: IndexMap<String, Parameter>,
 
         /// Key name for the signed URL field in an authorizationApi response
         #[serde(skip_serializing_if = "Option::is_none", rename = "responseField")]
@@ -138,7 +138,7 @@ pub struct Parameter {
     pub description: Option<String>,
 
     /// Schema object following the [JSON Schema draft-07](Schema object following the JSON Schema draft-07).
-    pub schema: HashMap<String, Value>,
+    pub schema: IndexMap<String, Value>,
 }
 
 /// Query, header, or cookie.