Example in readme doesn't compile

[dlight]

After wrapping the code on fn main() { }, here it fails compilation with:

Compiler error

error[E0432]: unresolved import `pg_embed::fetch`
 --> src/main.rs:2:5
  |
2 | use pg_embed::fetch;
  |     ^^^^^^^^^^^^^^^ no `fetch` in the root

error[E0432]: unresolved import `pg_embed::fetch`
 --> src/main.rs:3:15
  |
3 | use pg_embed::fetch::{PgFetchSettings, PG_V13};
  |               ^^^^^ could not find `fetch` in `pg_embed`

error[E0425]: cannot find value `pg` in this scope
  --> src/main.rs:69:25
   |
69 |     let pg_uri: &str = &pg.db_uri;
   |                         ^^ not found in this scope

error[E0425]: cannot find value `pg` in this scope
  --> src/main.rs:73:29
   |
73 |     let pg_db_uri: String = pg.full_db_uri("database_name");
   |                             ^^ not found in this scope

error[E0603]: enum `PgAuthMethod` is private
  --> src/main.rs:1:47
   |
1  | use pg_embed::postgres::{PgEmbed, PgSettings, PgAuthMethod};
   |                                               ^^^^^^^^^^^^ private enum
   |
note: the enum `PgAuthMethod` is defined here
  --> /home/me/.cargo/registry/src/github.com-1ecc6299db9ec823/pg-embed-0.6.1/src/postgres.rs:27:23
   |
27 | use crate::pg_enums::{PgAuthMethod, PgServerStatus};
   |                       ^^^^^^^^^^^^

warning: unused doc comment
  --> src/main.rs:9:1
   |
9  |   /// Postgresql settings
   |   ^^^^^^^^^^^^^^^^^^^^^^^
10 | / let pg_settings = PgSettings{
11 | |     // Where to store the postgresql database
12 | |     database_dir: PathBuf::from("data/db"),
13 | |     port: 5432,
...  |
27 | |     migration_dir: None,
28 | | };
   | |__- rustdoc does not generate documentation for statements
   |
   = note: `#[warn(unused_doc_comments)]` on by default

warning: unused doc comment
  --> src/main.rs:30:1
   |
30 |   /// Postgresql binaries download settings
   |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
31 | / let fetch_settings = PgFetchSettings{
32 | |        version: PG_V13,
33 | |        ..Default::default()
34 | | };
   | |__- rustdoc does not generate documentation for statements

warning: unused doc comment
  --> src/main.rs:37:1
   |
37 |   /// async block only to show that these methods need to be executed in an async context
   |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
38 | / async { 
39 | |     // Create a new instance
40 | |     let mut pg = PgEmbed::new(pg_settings, fetch_settings).await?;
41 | |
...  |
65 | |     pg.stop_db().await;
66 | | };
   | |_- rustdoc does not generate documentation for expressions

error[E0277]: the `?` operator can only be used in an async block that returns `Result` or `Option` (or another type that implements `FromResidual`)
  --> src/main.rs:40:65
   |
38 |   async { 
   |  _______-
39 | |     // Create a new instance
40 | |     let mut pg = PgEmbed::new(pg_settings, fetch_settings).await?;
   | |                                                                 ^ cannot use the `?` operator in an async block that returns `()`
41 | |
...  |
65 | |     pg.stop_db().await;
66 | | };
   | |_- this function should return `Result` or `Option` to accept `?`
   |
   = help: the trait `FromResidual<Result<Infallible, PgEmbedError>>` is not implemented for `()`
   = note: required by `from_residual`

error: aborting due to 6 previous errors; 3 warnings emitted

Some errors have detailed explanations: E0425, E0432, E0603.
For more information about an error, try `rustc --explain E0425`.
error: could not compile `pgexample`

The ? error isn't too important (I guess I could just do fn main() -> Result<..> { }, but the unresolved import errors seem to indicate the code example is for another version of pg-embed.

Are there other examples? Or some repository on Github that use pg-embed to do something.

[faokunega]

Hi,
the example in the README isn't meant to be run, it's just a quick overview of all the available methods.
Just take a look in the tests folder, the following files will show you how to use it
common.rs, migration_tokio.rs and postgres_tokio.rs
Cheers :)

[faokunega]

.... and I will update the example so that this won't happen anymore.
Thanks for the hint

[dlight]

Thanks!

[christopinka]

This compiles

use config::Config;
use apps_data::DBManager;
use pg_embed::postgres::{PgEmbed, PgSettings};
use pg_embed::pg_enums::PgAuthMethod;
use pg_embed::pg_fetch;
use pg_embed::pg_fetch::{PgFetchSettings, PG_V13};
use std::time::Duration;
use std::path::PathBuf;



#[test]
fn test_connect() {
    let mut settings = Config::new();

    settings.set_default("database.user", "postgres").unwrap();
    settings.set_default("database.password", "password").unwrap();
    settings.set_default("database.host", "172.17.0.3").unwrap();
    settings.set_default("database.dbname", "hmi").unwrap();
    settings.set_default("database.port", "5432").unwrap();

    println!("{:?}", settings);


    db_init();
    let mut dbman = DBManager::new(&settings);


    let conn = dbman.connected();
    println!("connected: {}", conn);
    assert!(conn, "database not connected");
}

// async fn main() -> Result<(), Box<dyn std::error::Error>>
async fn db_init() -> Result<(), Box<dyn std::error::Error>> {
    // Postgresql settings
    let pg_settings = PgSettings {
        // Where to store the postgresql database
        database_dir: PathBuf::from("data/db"),
        port: 5432,
        user: "postgres".to_string(),
        password: "password".to_string(),
        // authentication method
        auth_method: PgAuthMethod::Plain,
        // If persistent is false clean up files and directories on drop, otherwise keep them
        persistent: false,
        // duration to wait before terminating process execution
        // pg_ctl start/stop and initdb timeout
        // if set to None the process will not be terminated
        timeout: Some(Duration::from_secs(15)),
        // If migration sql scripts need to be run, the directory containing those scripts can be
        // specified here with `Some(PathBuf(path_to_dir)), otherwise `None` to run no migrations.
        // To enable migrations view the **Usage** section for details
        migration_dir: None,
    };

    // Postgresql binaries download settings
    let fetch_settings = PgFetchSettings {
        version: PG_V13,
        ..Default::default()
    };


    // async block only to show that these methods need to be executed in an async context

    // Create a new instance
    let mut pg = PgEmbed::new(pg_settings, fetch_settings).await?;

    // Download, unpack, create password file and database cluster
    pg.setup().await;

    // start postgresql database
    pg.start_db().await;

    // create a new database
    // to enable migrations view the [Usage] section for details
    pg.create_database("database_name").await;

    // drop a database
    // to enable migrations view [Usage] for details
    pg.drop_database("database_name").await;

    // check database existence
    // to enable migrations view [Usage] for details
    pg.database_exists("database_name").await;

    // run migration sql scripts
    // to enable migrations view [Usage] for details
    pg.migrate("database_name").await;

    // stop postgresql database
    pg.stop_db().await;

    // get the base postgresql uri
    // `postgres://{username}:{password}@localhost:{port}`
    let pg_uri: &str = &pg.db_uri;

    // get a postgresql database uri
    // `postgres://{username}:{password}@localhost:{port}/{specified_database_name}`
    let pg_db_uri: String = pg.full_db_uri("database_name");

    Ok(())
}