feat: support sqllogictest output coloring (#20368)

## Which issue does this PR close?

- Closes #20367.

## Rationale for this change

It's more ergonomic to have colored diffs in sqllogictest's output. 

The upstream library already supports it, and we can enable it based on
the user's choice. This PR checks `NO_COLOR`, terminal settings,
`CARGO_TERM_COLOR` and `--color` CLI argument. By default, the diff is
colored.

<img width="1243" height="338" alt="Screenshot 2026-02-15 at 11 44 05"
src="https://github.com/user-attachments/assets/a0aec386-ff33-4935-9a58-ba96fcd4ceb8"
/>

## What changes are included in this PR?

- sqllogictest driver output colouring with argument/flags analysis

## Are these changes tested?

- Tested different flag combinations

## Are there any user-facing changes?

---------

Signed-off-by: theirix <theirix@gmail.com>

Author: theirix

datafusion/sqllogictest/bin/sqllogictests.rs

@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use clap::Parser;
+use clap::{ColorChoice, Parser};
 use datafusion::common::instant::Instant;
 use datafusion::common::utils::get_available_parallelism;
 use datafusion::common::{DataFusionError, Result, exec_datafusion_err, exec_err};
@@ -44,7 +44,9 @@ use datafusion::common::runtime::SpawnedTask;
 use futures::FutureExt;
 use std::ffi::OsStr;
 use std::fs;
+use std::io::{IsTerminal, stdout};
 use std::path::{Path, PathBuf};
+use std::str::FromStr;
 
 #[cfg(feature = "postgres")]
 mod postgres_container;
@@ -123,6 +125,8 @@ async fn run_tests() -> Result<()> {
     .unwrap()
     .progress_chars("##-");
 
+    let colored_output = options.is_colored();
+
     let start = Instant::now();
 
     let test_files = read_test_files(&options)?;
@@ -176,6 +180,7 @@ async fn run_tests() -> Result<()> {
                             m_style_clone,
                             filters.as_ref(),
                             currently_running_sql_tracker_clone,
+                            colored_output,
                         )
                         .await?
                     }
@@ -187,6 +192,7 @@ async fn run_tests() -> Result<()> {
                             m_style_clone,
                             filters.as_ref(),
                             currently_running_sql_tracker_clone,
+                            colored_output,
                         )
                         .await?
                     }
@@ -294,6 +300,7 @@ async fn run_test_file_substrait_round_trip(
     mp_style: ProgressStyle,
     filters: &[Filter],
     currently_executing_sql_tracker: CurrentlyExecutingSqlTracker,
+    colored_output: bool,
 ) -> Result<()> {
     let TestFile {
         path,
@@ -323,7 +330,7 @@ async fn run_test_file_substrait_round_trip(
     runner.with_column_validator(strict_column_validator);
     runner.with_normalizer(value_normalizer);
     runner.with_validator(validator);
-    let res = run_file_in_runner(path, runner, filters).await;
+    let res = run_file_in_runner(path, runner, filters, colored_output).await;
     pb.finish_and_clear();
     res
 }
@@ -335,6 +342,7 @@ async fn run_test_file(
     mp_style: ProgressStyle,
     filters: &[Filter],
     currently_executing_sql_tracker: CurrentlyExecutingSqlTracker,
+    colored_output: bool,
 ) -> Result<()> {
     let TestFile {
         path,
@@ -364,7 +372,7 @@ async fn run_test_file(
     runner.with_column_validator(strict_column_validator);
     runner.with_normalizer(value_normalizer);
     runner.with_validator(validator);
-    let result = run_file_in_runner(path, runner, filters).await;
+    let result = run_file_in_runner(path, runner, filters, colored_output).await;
     pb.finish_and_clear();
     result
 }
@@ -373,6 +381,7 @@ async fn run_file_in_runner<D: AsyncDB, M: MakeConnection<Conn = D>>(
     path: PathBuf,
     mut runner: sqllogictest::Runner<D, M>,
     filters: &[Filter],
+    colored_output: bool,
 ) -> Result<()> {
     let path = path.canonicalize()?;
     let records =
@@ -386,7 +395,11 @@ async fn run_file_in_runner<D: AsyncDB, M: MakeConnection<Conn = D>>(
             continue;
         }
         if let Err(err) = runner.run_async(record).await {
-            errs.push(format!("{err}"));
+            if colored_output {
+                errs.push(format!("{}", err.display(true)));
+            } else {
+                errs.push(format!("{err}"));
+            }
         }
     }
 
@@ -479,7 +492,7 @@ async fn run_test_file_with_postgres(
     runner.with_column_validator(strict_column_validator);
     runner.with_normalizer(value_normalizer);
     runner.with_validator(validator);
-    let result = run_file_in_runner(path, runner, filters).await;
+    let result = run_file_in_runner(path, runner, filters, false).await;
     pb.finish_and_clear();
     result
 }
@@ -772,6 +785,14 @@ struct Options {
         default_value_t = get_available_parallelism()
     )]
     test_threads: usize,
+
+    #[clap(
+        long,
+        value_name = "MODE",
+        help = "Control colored output",
+        default_value_t = ColorChoice::Auto
+    )]
+    color: ColorChoice,
 }
 
 impl Options {
@@ -813,6 +834,37 @@ impl Options {
             eprintln!("WARNING: Ignoring `--show-output` compatibility option");
         }
     }
+
+    /// Determine if colour output should be enabled, respecting --color, NO_COLOR, CARGO_TERM_COLOR, and terminal detection
+    fn is_colored(&self) -> bool {
+        // NO_COLOR takes precedence
+        if std::env::var_os("NO_COLOR").is_some() {
+            return false;
+        }
+
+        match self.color {
+            ColorChoice::Always => true,
+            ColorChoice::Never => false,
+            ColorChoice::Auto => {
+                // CARGO_TERM_COLOR takes precedence over auto-detection
+                let cargo_term_color = ColorChoice::from_str(
+                    &std::env::var("CARGO_TERM_COLOR")
+                        .unwrap_or_else(|_| "auto".to_string()),
+                )
+                .unwrap_or(ColorChoice::Auto);
+                match cargo_term_color {
+                    ColorChoice::Always => true,
+                    ColorChoice::Never => false,
+                    ColorChoice::Auto => {
+                        // Auto for both CLI argument and CARGO_TERM_COLOR,
+                        // then use colors by default for non-dumb terminals
+                        stdout().is_terminal()
+                            && std::env::var("TERM").unwrap_or_default() != "dumb"
+                    }
+                }
+            }
+        }
+    }
 }
 
 /// Performs scratch file check for all test files.