Add a repr method to Snapshot.

Author: nedtwigg

python/selfie-lib/selfie_lib/Snapshot.py

@@ -87,3 +87,9 @@ def of_items(items: Iterator[tuple[str, SnapshotValue]]) -> "Snapshot":
     def items(self) -> Iterator[tuple[str, SnapshotValue]]:
         yield ("", self._subject)
         yield from self._facet_data.items()
+
+    def __repr__(self) -> str:
+        pieces = [f"Snapshot.of({self.subject.value_string()!r})"]
+        for e in self.facets.items():
+            pieces.append(f"\n  .plus_facet({e[0]!r}, {e[1].value_string()!r})")  # noqa: PERF401
+        return "".join(pieces)

python/selfie-lib/tests/Snapshot_test.py

@@ -7,3 +7,20 @@ def test_items():
     )
     roundtrip = Snapshot.of_items(undertest.items())
     assert roundtrip == undertest
+
+
+def test_repr():
+    assert repr(Snapshot.of("subject")) == "Snapshot.of('subject')"
+    assert repr(Snapshot.of("subject\nline2")) == "Snapshot.of('subject\\nline2')"
+    assert (
+        repr(Snapshot.of("subject").plus_facet("apple", "green"))
+        == "Snapshot.of('subject')\n  .plus_facet('apple', 'green')"
+    )
+    assert (
+        repr(
+            Snapshot.of("subject")
+            .plus_facet("orange", "peel")
+            .plus_facet("apple", "green")
+        )
+        == "Snapshot.of('subject')\n  .plus_facet('apple', 'green')\n  .plus_facet('orange', 'peel')"
+    )