migrate azure_identity to azure_core::error::Error

[ctaggart]

Changes:

• Removes thiserror errors & replaces with azure_core::error::Error
• Removes identity::TokenCredential
• get_token switched to azure_core::error::Error
• changes Error::with_message to accept a FnOnce like ResultExt::with_context.
• Adds Error::message, similar to ResultExt::context.
• refresh_token error handling now checks response status

[ctaggart]

I had to show myself what format! does under the covers.

fn calc(s: impl Into<String>){
    s.into();
}

fn main() {
    calc(format!("Hello, world!"));
}

output from cargo expand:

#![feature(prelude_import)]
#[prelude_import]
use std::prelude::rust_2021::*;
#[macro_use]
extern crate std;
fn calc(s: impl Into<String>) {
    s.into();
}
fn main() {
    calc({
        let res = ::alloc::fmt::format(::core::fmt::Arguments::new_v1(&["Hello, world!"], &[]));
        res
    });
}

So yes, it is better to use a || format!.

[ctaggart]

More similar with ResultExt::context

[ctaggart]

Takes a function like ResultExt::with_context. What about naming message_fn or event messagef?

[johnbatty]

I'm happy with the current naming. The context/with_context naming matches that of the corresponding anyhow functions, so this does have the benefit of being familiar to existing anyhow users.

[johnbatty]

Mainly questions/clarifications about ErrorKind usage.

[johnbatty]

More ErrorKind suggestions... In my previous review I only gave a few as I wanted to know whether you agreed with the suggested changes. These cover the whole PR. Again, all are just suggestions so take or leave as you wish.

[johnbatty]

Looks good - approved.