Merge commit 'c91cc055c8ad81afd8f055b71c74af6819020637' into fix/headless-import-refusals

# Conflicts:
#	context/test-evidence/cli.md
#	context/test-evidence/formula-and-io.md
#	crates/improvise-io/src/import/wizard.rs
#	src/main.rs
#	tests/folder_import_views.rs
#	tests/headless_cli.rs

tests/folder_import_views.rs

@@ -19,15 +19,16 @@ fn reloaded_folder_import() -> App {
             "maat/coupling.csv",
             "entity,coupled,degree,average-revs\nsrc/a.rs,src/b.rs,80,5\nsrc/b.rs,src/c.rs,40,3\n",
         ),
+        ("maat/soc.csv", "entity,soc\n"),
     ];
     for (path, body) in files {
         fs.write(std::path::Path::new(path), body.as_bytes())
             .unwrap();
     }
     let merged = merge_csvs_from(&fs, &files.map(|(p, _)| p)).unwrap();
-    let mut pipeline = ImportPipeline::from_csv(merged.records);
-    pipeline.sources = merged.sources;
-    let (wb, _) = pipeline.build_model_with_warnings().unwrap();
+    let (wb, _) = ImportPipeline::from_merge(merged)
+        .build_model_with_warnings()
+        .unwrap();
     App::new(parse_md(&format_md(&wb)).unwrap(), None)
 }
 
@@ -54,4 +55,11 @@ fn a_saved_per_file_view_projects_only_its_file() {
             .collect();
         assert_eq!(drawn, texts, "{view}");
     }
+
+    // A header-only file: its item exists, and its view has nothing editable.
+    let soc = grid_in(&app, "soc", whole);
+    let file = soc.page_coords.iter().find(|p| p.cat == "File").unwrap();
+    assert_eq!(file.selected, "soc");
+    assert!(soc.records, "a file with no measure opens in records mode");
+    assert_eq!(soc.extent.rows, 0, "{soc:?}");
 }

tests/headless_cli.rs

@@ -822,3 +822,34 @@ fn an_import_that_skips_some_records_warns_with_a_count_and_still_writes() {
     let doc = std::fs::read_to_string(&out_path).unwrap();
     assert!(doc.contains("_Measure=x, a=m = 4"), "{doc}");
 }
+
+/// improvise-lpzu, the user's ruling: a folder always merges, so even one CSV
+/// keeps its file identity. Evidence: `context/test-evidence/cli.md`.
+#[test]
+fn a_folder_of_one_csv_still_gets_a_file_category_and_its_view_but_a_lone_file_does_not() {
+    let scratch = Scratch::new("folder_single");
+    let dir = scratch.path("one");
+    std::fs::create_dir_all(&dir).unwrap();
+    let csv = dir.join("age.csv");
+    std::fs::write(&csv, "entity,age-months\nsrc/a.rs,2\n").unwrap();
+
+    let from_folder = scratch.path("folder.improv");
+    let out = run_import(&dir, &from_folder, &[]);
+    assert!(out.status.success(), "{}", stderr_of(&out));
+    let doc = std::fs::read_to_string(&from_folder).unwrap();
+    assert!(doc.contains("## Category: File\n- age\n"), "{doc}");
+    assert!(doc.lines().any(|l| l == "File: filter, age"), "{doc}");
+    assert!(
+        doc.contains("File=age, _Measure=age-months, entity=|src/a.rs| = 2"),
+        "{doc}"
+    );
+
+    let from_file = scratch.path("file.improv");
+    let out = run_import(&csv, &from_file, &[]);
+    assert!(out.status.success(), "{}", stderr_of(&out));
+    let doc = std::fs::read_to_string(&from_file).unwrap();
+    assert!(
+        !doc.contains("File"),
+        "a lone file keeps today's shape: {doc}"
+    );
+}