cli: add basic error reporting using anyhow

CHANGELOG.md

@@ -1,5 +1,24 @@
 # Unreleased (Yet)
 
+## v0.5.0 (2024-12-17)
+
+- Added basic error reporting. For example, the CLI might now tell you:
+  - ```
+    Error:
+    Failed to parse response body as JSON
+
+    Caused by:
+        0: error decoding response body
+        1: missing field `webUrl2` at line 1 column 308
+    ```
+  - ```
+    Error:
+    Failed to receive proper response
+
+    Caused by:
+        HTTP status client error (401 Unauthorized) for url (https://gitlab.vpn.cyberus-technology.de/api/graphql)
+    ```
+
 ## v0.4.1 (2024-12-17)
 
 - Better error reporting: it is now clearer if the request failed due to a

Cargo.toml

@@ -19,6 +19,7 @@ authors = [
 ]
 
 [dependencies]
+anyhow = "1.0.94"
 chrono = { version = "0.4.38", default-features = false, features = ["clock", "std", "serde"] }
 nu-ansi-term = "0.50.0"
 reqwest = { version =  "0.12.4", features = ["blocking", "json"] }

src/fetch.rs

@@ -27,6 +27,7 @@ SOFTWARE.
 //! [`fetch_results`] is the entry point.
 
 use crate::gitlab_api::types::Response;
+use anyhow::Context;
 use chrono::{DateTime, Local, NaiveDate, NaiveTime};
 use reqwest::blocking::Client;
 use reqwest::header::AUTHORIZATION;
@@ -61,7 +62,7 @@ fn fetch_result(
     before: Option<&str>,
     start_date: NaiveDate,
     end_date: NaiveDate,
-) -> Response {
+) -> anyhow::Result<Response> {
     let graphql_query = GRAPHQL_TEMPLATE
         .replace("%USERNAME%", username)
         .replace("%BEFORE%", before.unwrap_or_default())
@@ -85,19 +86,18 @@ fn fetch_result(
     let url = format!("https://{host}/api/graphql", host = host);
     let client = Client::new();
 
-    match client
+    let plain_response = client
         .post(url)
         .header(AUTHORIZATION, authorization)
         .json(&payload)
         .send()
-        .unwrap()
+        .context("Failed to send request")?
         .error_for_status()
-    {
-        Ok(response) => response.json::<Response>().unwrap(),
-        Err(err) => {
-            panic!("Request to Gitlab failed: {err}")
-        }
-    }
+        .context("Failed to receive proper response")?;
+
+    plain_response
+        .json::<Response>()
+        .context("Failed to parse response body as JSON")
 }
 
 /// Fetches all results from the API with pagination in mind.
@@ -115,8 +115,8 @@ pub fn fetch_results(
     token: &str,
     start_date: NaiveDate,
     end_date: NaiveDate,
-) -> Response {
-    let base = fetch_result(username, host, token, None, start_date, end_date);
+) -> anyhow::Result<Response> {
+    let base = fetch_result(username, host, token, None, start_date, end_date)?;
 
     let mut aggregated = base;
     while aggregated.data.timelogs.pageInfo.hasPreviousPage {
@@ -134,7 +134,7 @@ pub fn fetch_results(
             ),
             start_date,
             end_date,
-        );
+        )?;
 
         // Ordering here is not that important, happens later anyway.
         next.data
@@ -143,5 +143,5 @@ pub fn fetch_results(
             .extend(aggregated.data.timelogs.nodes);
         aggregated = next;
     }
-    aggregated
+    Ok(aggregated)
 }

src/main.rs

@@ -45,6 +45,7 @@ use crate::cfg::get_cfg;
 use crate::cli::CliArgs;
 use crate::fetch::fetch_results;
 use crate::gitlab_api::types::ResponseNode;
+use anyhow::{anyhow, Context};
 use chrono::{Datelike, NaiveDate, Weekday};
 use nu_ansi_term::{Color, Style};
 use std::error::Error;
@@ -58,18 +59,24 @@ mod views;
 
 fn main() -> Result<(), Box<dyn Error>> {
     let cfg = get_cfg()?;
-    assert!(cfg.before() >= cfg.after());
-    println!("Host     : {}", cfg.host());
-    println!("Username : {}", cfg.username());
-    println!("Time Span: {} - {}", cfg.after(), cfg.before());
+    if cfg.before() < cfg.after() {
+        Err(anyhow!(
+            "The `--before` date must come after the `--after` date"
+        ))
+        .context("Failed to validate config")?;
+    }
 
     let response = fetch_results(
         cfg.username(),
         cfg.host(),
         cfg.token(),
         cfg.after(),
         cfg.before(),
-    );
+    )?;
+
+    println!("Host     : {}", cfg.host());
+    println!("Username : {}", cfg.username());
+    println!("Time Span: {} - {}", cfg.after(), cfg.before());
 
     // All nodes but as vector to references.
     // Simplifies the handling with other parts of the code, especially the