test(runner): element-valued extractors reach the trace

internal/runner/element_extractor_trace_test.go

@@ -0,0 +1,135 @@
+package runner
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/priyanshujain/sanderling/internal/trace"
+)
+
+// elementExtractorSpec records accessibility elements directly, the shape an
+// author reaches for when the question is "what was on screen at this step":
+// one element and the list a generator would have been offered.
+const elementExtractorSpec = `
+import { actions, extract } from "@sanderling/spec";
+extract("field", state => state.ax.find({ testTag: "LoginEmail" }));
+extract("rows", state => state.ax.findAll({ testTag: "Row" }));
+globalThis.properties = {};
+globalThis.actions = actions(() => []);
+`
+
+const elementExtractorHierarchy = `{
+  "attributes": {"class": "android.widget.LinearLayout", "bounds": "[0,0,1080,2340]"},
+  "children": [
+    {"attributes": {"resource-id": "LoginEmail", "class": "android.widget.EditText",
+      "text": "[email protected]", "bounds": "[10,20,200,60]"}, "children": []},
+    {"attributes": {"resource-id": "Row", "class": "android.widget.TextView",
+      "text": "first", "bounds": "[0,100,1080,200]"}, "children": []},
+    {"attributes": {"resource-id": "Row", "class": "android.widget.TextView",
+      "text": "second", "bounds": "[0,200,1080,300]"}, "children": []}
+  ]
+}`
+
+// TestRunner_TraceRecordsElementValuedExtractors pins that an extractor holding
+// an accessibility element reaches the trace. Elements carry host functions
+// (find/findAll), which json.Marshal refuses; the encoder used to answer nil
+// and the diff then emitted no entry, so the run finished clean with the
+// extractor missing from every step and no error anywhere.
+func TestRunner_TraceRecordsElementValuedExtractors(t *testing.T) {
+	state := newHarnessWithSpec(t, elementExtractorSpec)
+	state.mock.HierarchyJSON = elementExtractorHierarchy
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	if _, err := Run(ctx, Options{
+		Duration:    100 * time.Millisecond,
+		IdleTimeout: 20 * time.Millisecond,
+		Driver:      state.mock,
+		Verifier:    state.verifier,
+		TraceWriter: state.writer,
+	}); err != nil {
+		t.Fatalf("Run: %v", err)
+	}
+
+	field, rows := elementChangesFromTrace(t, state.directory)
+	if field == nil {
+		t.Fatal("no extractor change for the element-valued extractor reached the trace")
+	}
+	if rows == nil {
+		t.Fatal("no extractor change for the element-list extractor reached the trace")
+	}
+
+	var element map[string]any
+	if err := json.Unmarshal(field, &element); err != nil {
+		t.Fatalf("field value is not a JSON object: %v (%s)", err, field)
+	}
+	if got := element["id"]; got != "LoginEmail" {
+		t.Errorf("field.id = %v, want LoginEmail", got)
+	}
+	if got := element["text"]; got != "[email protected]" {
+		t.Errorf("field.text = %v, want [email protected]", got)
+	}
+	if got := element["class"]; got != "android.widget.EditText" {
+		t.Errorf("field.class = %v, want android.widget.EditText", got)
+	}
+	bounds, ok := element["bounds"].(map[string]any)
+	if !ok {
+		t.Fatalf("field.bounds missing or not an object: %v", element["bounds"])
+	}
+	if bounds["left"] != float64(10) || bounds["top"] != float64(20) ||
+		bounds["right"] != float64(200) || bounds["bottom"] != float64(60) {
+		t.Errorf("field.bounds = %v, want left/top/right/bottom 10/20/200/60", bounds)
+	}
+	for _, key := range []string{"find", "findAll"} {
+		if _, present := element[key]; present {
+			t.Errorf("field carries the host function %q into the trace", key)
+		}
+	}
+
+	var list []map[string]any
+	if err := json.Unmarshal(rows, &list); err != nil {
+		t.Fatalf("rows value is not a JSON array: %v (%s)", err, rows)
+	}
+	if len(list) != 2 {
+		t.Fatalf("rows recorded %d elements, want 2", len(list))
+	}
+	if list[0]["text"] != "first" || list[1]["text"] != "second" {
+		t.Errorf("rows recorded %v, want the two Row elements in tree order", list)
+	}
+}
+
+// elementChangesFromTrace returns the first recorded value of each extractor.
+func elementChangesFromTrace(t *testing.T, directory string) (field, rows json.RawMessage) {
+	t.Helper()
+	file, err := os.Open(filepath.Join(directory, "trace.jsonl"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	scanner.Buffer(make([]byte, 0, 64*1024), 8*1024*1024)
+	for scanner.Scan() {
+		var line struct {
+			ExtractorChanges map[string]trace.ExtractorChange `json:"extractor_changes"`
+		}
+		if err := json.Unmarshal(scanner.Bytes(), &line); err != nil {
+			t.Fatalf("trace line decode: %v", err)
+		}
+		if change, ok := line.ExtractorChanges["field"]; ok && field == nil {
+			field = change.Curr
+		}
+		if change, ok := line.ExtractorChanges["rows"]; ok && rows == nil {
+			rows = change.Curr
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		t.Fatalf("scan trace: %v", err)
+	}
+	return field, rows
+}