fix: `--env` flag confusing message on syntax error (#23915)

Enhanced warning message for --env flag with run and eval subcommands. 

The commit is specifically made to address issue #23674 by improving the
warning messages that appear when using the --env flag with run or eval
subcommands in the following scenarios:

1. Missing environment file.
2. Incorrect syntax in the environment file content.


**Changes made**

- Distinguishes between cases of missing environment file and wrong
syntax in the environment file content.
- Shows a concise warning message to convey the case/issue occurred.

**Code changes & enhancements**
- Implemented a match statement to handle different types of errors
received while getting and parsing the file content to display a concise
warning message, rather than simple error check and then displaying the
same warning message for whatever the type of error is.
- Updated the related existing tests to reflect the new warning
messages.
- Added two test cases to cover the wrong environment file content
syntax with both run and eval subcommands.

**Impact**
The use of --env flag with both run/eval would be more user-friendly as
it gives a precise description of what is not right when using
incorrectly.

If you could give it a look, @dsherret , I appreciate your feedback on
these changes.

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

1 files changed, 11 insertions, 7 deletions

diff --git a/cli/args/mod.rs b/cli/args/mod.rs
index bc384a132..706d98852 100644
--- a/cli/args/mod.rs
+++ b/cli/args/mod.rs
@@ -857,13 +857,17 @@ impl CliOptions {
       };
 
     if let Some(env_file_name) = &flags.env_file {
-      if (from_filename(env_file_name)).is_err() {
-        log::info!(
-          "{} The `--env` flag was used, but the dotenv file '{}' was not found.",
-          colors::yellow("Warning"),
-          env_file_name
-        );
-      }
+      match from_filename(env_file_name) {
+          Ok(_) => (),
+          Err(error) => {
+            match error {
+              dotenvy::Error::LineParse(line, index)=> log::info!("{} Parsing failed within the specified environment file: {} at index: {} of the value: {}",colors::yellow("Warning"), env_file_name, index, line),
+              dotenvy::Error::Io(_)=> log::info!("{} The `--env` flag was used, but the environment file specified '{}' was not found.",colors::yellow("Warning"),env_file_name),
+              dotenvy::Error::EnvVar(_)=>log::info!("{} One or more of the environment variables isn't present or not unicode within the specified environment file: {}",colors::yellow("Warning"),env_file_name),
+              _ => log::info!("{} Unknown failure occurred with the specified environment file: {}", colors::yellow("Warning"), env_file_name),
+            }
+          }
+        }
     }
 
     let disable_deprecated_api_warning = flags.log_level