Add hello world example (#360)

* Add hello world example

* Update wasm

* Update scripts

* Update docs

* update hello readme

* update docs + schema

* Update docs

Co-authored-by: Rashad Alston <rashad@Rashads-MacBook-Pro.local>

Cargo.toml

@@ -3,6 +3,8 @@
 resolver = "2"
 members = [
    "examples/block-explorer/explorer-index",
+   "examples/hello-world/hello-bin",
+   "examples/hello-world/hello-index",
    "examples/simple-wasm/simple-wasm",
    "examples/simple-wasm/simple",
    "packages/fuel-indexer-api-server",

README.md

@@ -26,5 +26,5 @@ DATABASE_URL=postgres://postgres@localhost bash scripts/run_migrations.bash
 ### Start the service
 
 ```bash
-cargo run --bin fuel-indexer -- --manifest fuel-indexer-tests/assets/fuel_indexer_test.yaml
+cargo run --bin fuel-indexer
 ```

docs/src/SUMMARY.md

@@ -10,6 +10,7 @@
     - [Configuration](./getting-started/configuration.md)
 - [Quickstart](./quickstart/index.md)
 - [Examples](./examples/index.md)
+  - [Hello World](./examples/hello-world.md)
   - [Block Explorer](./examples/block-explorer.md)
 - [Components](./components/index.md)
   - [Assets](./components/assets/index.md)

docs/src/examples/block-explorer.md

@@ -291,7 +291,7 @@ mod explorer_index {
 Once blocks have been added to the database by the indexer, you can query for them by using a query similar to the following:
 
 ```sh
-❯ curl -X POST http://127.0.0.1:29987/api/graph/fuel_examples \
+curl -X POST http://127.0.0.1:29987/api/graph/fuel_examples \
    -H 'content-type: application/json' \
    -d '{"query": "query { block { id height timestamp }}", "params": "b"}' \
 | json_pp

docs/src/examples/hello-world.md

@@ -0,0 +1,111 @@
+# Hello World
+
+A "Hello World" type of program for the Fuel Indexer service.
+
+```rust
+//! A rudimentary block explorer implementation demonstrating how blocks, transactions,
+//! contracts, and accounts can be persisted into the database.
+//!
+//! Build this example's WASM module using the following command. Note that a
+//! wasm32-unknown-unknown target will be required.
+//!
+//! ```bash
+//! cargo build -p hello-index --release --target wasm32-unknown-unknown
+//! ```
+//!
+//! Start a local test Fuel node
+//!
+//! ```bash
+//! cargo run --bin fuel-node
+//! ```
+//!
+//! With your database backend set up, now start your fuel-indexer binary using the
+//! assets from this example:
+//!
+//! ```bash
+//! cargo run --bin fuel-indexer -- --manifest examples/hello-world/hello-index.manifest.yaml
+//! ```
+//!
+//! Now trigger an event.
+//!
+//! ```bash
+//! cargo run --bin hello-bin
+//! ```
+
+extern crate alloc;
+use fuel_indexer_macros::indexer;
+use fuel_indexer_plugin::{types::Bytes32, utils::sha256_digest};
+
+// A utility function used to convert an arbitrarily sized string into Bytes32
+// using the first 32 bytes of the String. This might be provided by a standard-ish
+// library in the future.
+fn bytes32(data: &str) -> Bytes32 {
+    let data = sha256_digest(&data);
+    let mut buff = [0u8; 32];
+    buff.copy_from_slice(&data.as_bytes()[..32]);
+    Bytes32::from(buff)
+}
+
+// A utility function used to convert an arbitrarily sized string into u64
+// using the first 8 bytes of the String. This might be provided by a standard-ish
+// library in the future.
+fn u64_id(data: &str) -> u64 {
+    let mut buff = [0u8; 8];
+    buff.copy_from_slice(&data.as_bytes()[..8]);
+    u64::from_le_bytes(buff)
+}
+
+#[indexer(manifest = "examples/hello-world/hello-index.manifest.yaml")]
+mod hello_world_index {
+    fn index_logged_greeting(event: Greeting, block: BlockData) {
+        // Since all events require a u64 ID field, let's derive an ID using the
+        // name of the person in the Greeting
+        let greeter_id = u64_id(&event.person.name.to_string());
+
+        // Here we 'get or create' a Salutation based on the ID of the event
+        // emiited in the LogData receipt of our smart contract
+        let greeting = match Salutation::load(event.id) {
+            Some(mut g) => {
+                // If we found an event, let's use block height as a proxy for time
+                g.last_seen = block.height;
+                g
+            }
+            None => {
+                // If we did not already have this Saluation stored in the database. Here we
+                // show how you can use the String255 type to store strings with length <= 255
+                let message =
+                    format!("{} 👋, my name is {}", &event.greeting, &event.person.name);
+
+                Salutation {
+                    id: event.id,
+                    message_hash: bytes32(&message),
+                    message,
+                    greeter: greeter_id,
+                    first_seen: block.height,
+                    last_seen: block.height,
+                }
+            }
+        };
+
+        // Here we do the same with Greeter that we did for Saluation -- if we have an event
+        // already saved in the database, load it and update it. If we do not have this Greeter
+        // in the database then create one
+        let greeter = match Greeter::load(greeter_id) {
+            Some(mut g) => {
+                g.last_seen = block.height;
+                g
+            }
+            None => Greeter {
+                id: greeter_id,
+                first_seen: block.height,
+                name: event.person.name.to_string(),
+                last_seen: block.height,
+            },
+        };
+
+        // Both entity saves will occur in the same transaction
+        greeting.save();
+        greeter.save();
+    }
+}
+```

docs/src/examples/index.md

@@ -1,4 +1,6 @@
 # Examples
 
+- [Hello World](./hello-world.md)
+  - A "Hello World" type of program for the Fuel Indexer service.
 - [Block Explorer](./block-explorer.md)
   - An extremely basic block explorer implementation that shows how blocks, transactions, contracts, and accounts can be persisted into the database.

docs/src/getting-started/fuel-indexer-project.md

@@ -16,31 +16,22 @@ When running a Fuel indexer service as a standalone binary, you can just simply
 The convetion for a Fuel project layout including a Fuel indexer is:
 
 ```text
-➜  my-project tree . -I target/ -I out/
 .
 ├── contracts
-│   └── my-contract
-│       ├── Forc.lock
-│       ├── Forc.toml
-│       ├── out
-│       │   └── debug
-│       │       ├── my-contract-abi.json
-│       │       ├── my-contract-storage_slots.json
-│       │       └── my-contract.bin
-│       ├── src
-│       │   └── main.sw
-│       └── tests
-│           └── harness.rs
+│   └── greeting
+│       ├── Forc.toml
+│       └── src
+│           └── main.sw
 ├── frontend
-│   └── index.html
+│   └── index.html
 └── indexer
-    ├── my-index.manifest.yaml
-    ├── my-index
-    │   ├── Cargo.toml
-    │   └── src
-    │       └── lib.rs
-    └── schema
-        └── schema.graphql
-
-11 directories, 14 files
+    └── hello-index
+        ├── Cargo.toml
+        ├── hello-index.manifest.yaml
+        ├── schema
+        │   └── hello-index.schema.graphql
+        └── src
+            └── lib.rs
+
+8 directories, 7 files
 ```