Shared: Handle trap compression option properly

Extracting the compression setting from an environment variable is the
responsibility of the API consumer.

ql/extractor/src/extractor.rs

@@ -61,6 +61,7 @@ pub fn run(options: Options) -> std::io::Result<()> {
             },
         ],
         trap_dir: options.output_dir,
+        trap_compression: trap::Compression::from_env("CODEQL_QL_TRAP_COMPRESSION"),
         source_archive_dir: options.source_archive_dir,
         file_list: options.file_list,
     };

shared/tree-sitter-extractor/src/extractor/simple.rs

@@ -22,6 +22,10 @@ pub struct Extractor {
     pub trap_dir: PathBuf,
     pub source_archive_dir: PathBuf,
     pub file_list: PathBuf,
+    // Typically constructed via `trap::Compression::from_env`.
+    // This allow us to report the error using our diagnostics system
+    // without exposing it to consumers.
+    pub trap_compression: Result<trap::Compression, String>,
 }
 
 impl Extractor {
@@ -52,8 +56,8 @@ impl Extractor {
                 "threads"
             }
         );
-        let trap_compression = match trap::Compression::from_env("CODEQL_QL_TRAP_COMPRESSION") {
-            Ok(x) => x,
+        let trap_compression = match &self.trap_compression {
+            Ok(x) => *x,
             Err(e) => {
                 main_thread_logger.write(
                     main_thread_logger

shared/tree-sitter-extractor/tests/integration_test.rs

@@ -3,6 +3,7 @@ use std::io::{Read, Write};
 use std::path::{Path, PathBuf};
 
 use codeql_extractor::extractor::simple;
+use codeql_extractor::trap;
 use flate2::read::GzDecoder;
 use tree_sitter_ql;
 
@@ -47,6 +48,7 @@ fn simple_extractor() {
         trap_dir,
         source_archive_dir,
         file_list,
+        trap_compression: Ok(trap::Compression::Gzip),
     };
 
     // The extractor should run successfully