rewrite comments in neutral, terse style

Doc comments, inline comments, and README no longer editorialize about
the code (ActiveRecord, leak, fake, Yak before/after). They now describe
behavior only. Test A_client_can_reach_its_DbContext__the_leak renamed
to A_client_can_reach_its_DbContext. No behavior changes; all 27 tests
pass.
This commit is contained in:
2026-09-15 17:26:15 +01:00
parent 0d19a1f171
commit d60ea160c4
9 changed files with 99 additions and 354 deletions
+34 -112
View File
@@ -3,15 +3,11 @@ using Before;
namespace BeforeAfter.Tests;
/// <summary>
/// Tests for the BEFORE situation (Yak 01): DB-backed domain classes that
/// inherit <see cref="DbBase"/> and leak their <see cref="DbContext"/>.
/// Tests for the Client, Order, DbBase, DbContext, and WebApp classes.
/// </summary>
public class BeforeTests
{
// ---------------------------------------------------------------------
// (1) Inheritance: the domain classes ARE DB-backed (they derive from
// DbBase). This is the "before" shape Yak 02 will undo.
// ---------------------------------------------------------------------
// Client and Order derive from DbBase.
[Fact]
public void Client_and_Order_derive_from_DbBase()
{
@@ -19,9 +15,7 @@ public class BeforeTests
Assert.True(typeof(DbBase).IsAssignableFrom(typeof(Order)));
}
// ---------------------------------------------------------------------
// (2) Fresh entities are unsaved: their Id is still Guid.Empty.
// ---------------------------------------------------------------------
// New entities have Id == Guid.Empty.
[Theory]
[InlineData(typeof(Client))]
[InlineData(typeof(Order))]
@@ -31,10 +25,7 @@ public class BeforeTests
Assert.Equal(Guid.Empty, entity.Id);
}
// ---------------------------------------------------------------------
// (3) Save() fakes EF's SaveChanges: it assigns fresh, distinct Guids to
// entities that do not have one yet.
// ---------------------------------------------------------------------
// Save assigns fresh, distinct Guids to unsaved entities.
[Fact]
public void Save_assigns_fresh_distinct_ids()
{
@@ -51,10 +42,7 @@ public class BeforeTests
Assert.NotEqual(acme.Id, globex.Id);
}
// ---------------------------------------------------------------------
// (4) A saved entity is registered with its context, reachable via the
// active-record back-reference.
// ---------------------------------------------------------------------
// A saved entity references its context and is tracked by it.
[Fact]
public void Saved_entity_is_registered_with_its_context()
{
@@ -67,10 +55,7 @@ public class BeforeTests
Assert.True(db.IsTracked(client));
}
// ---------------------------------------------------------------------
// (5) Navigation fix-up: adding an order to client.Orders wires the
// order.Client back-reference.
// ---------------------------------------------------------------------
// Adding an order to client.Orders sets order.Client.
[Fact]
public void Adding_an_order_sets_the_client_back_reference()
{
@@ -84,30 +69,21 @@ public class BeforeTests
Assert.Single(client.Orders);
}
// ---------------------------------------------------------------------
// (6) THE LEAK: from a plain Client you can reach its DbContext.
// This is exactly what the "after" situation removes: a ClientDto has
// no DbContext to reach, so a consumer can never touch the persistence
// layer through it.
// ---------------------------------------------------------------------
// A client exposes the context it was attached to.
[Fact]
public void A_client_can_reach_its_DbContext__the_leak()
public void A_client_can_reach_its_DbContext()
{
var db = new DbContext();
var client = new Client { Name = "Acme" };
db.Attach(client);
db.Save();
// Reaching the persistence layer *through* the domain object:
Assert.NotNull(client.DbContext);
Assert.Same(db, client.DbContext);
Assert.True(client.DbContext!.IsTracked(client));
}
// ---------------------------------------------------------------------
// (7) The WebApp consumes the domain classes directly — including a method
// that rides the leak.
// ---------------------------------------------------------------------
// WebApp works on domain classes directly.
[Fact]
public void WebApp_works_on_the_domain_classes_directly()
{
@@ -121,17 +97,14 @@ public class BeforeTests
db.Attach(order);
db.Save();
// ShowClient consumes Client and its Orders directly:
var view = app.ShowClient(client);
Assert.Contains("Acme", view);
Assert.Contains("order one", view);
// IsPersisted rides the leak (client.DbContext) — and it is true here
// because the client was saved through the context:
Assert.True(app.IsPersisted(client));
}
// A companion check: a bare client has no context until saved.
// A bare client has no context until saved.
[Fact]
public void A_bare_client_has_no_context_until_saved()
{
@@ -142,29 +115,21 @@ public class BeforeTests
Assert.False(app.IsPersisted(client));
}
// -----------------------------------------------------------------
// (8) Static Context (Singleton): DbBase exposes a class-level
// shared DbContext. Setting it makes the context accessible
// from any entity via its base type.
// -----------------------------------------------------------------
// DbBase exposes a static, shared Context reference.
[Fact]
public void DbBase_has_a_static_Context_singleton()
{
Assert.Null(DbBase.Context); // fresh — not set yet
Assert.Null(DbBase.Context);
var db = new DbContext();
DbBase.Context = db;
Assert.Same(db, DbBase.Context);
DbBase.Context = null; // cleanup
DbBase.Context = null; // cleanup
}
// ---------------------------------------------------------------------
// (9) ActiveRecord finder: DbBase.Find<T> walks the context's tracked
// entities, looks for the first whose runtime type matches T,
// and returns it when <paramref name="predicate"/> matches.
// ---------------------------------------------------------------------
// DbBase.Find returns the first tracked entity of type T matching the predicate.
[Fact]
public void DbBase_Find_finds_matching_entity()
{
@@ -180,10 +145,7 @@ public class BeforeTests
Assert.Same(globex, result);
}
// ---------------------------------------------------------------------
// (10) DbBase.Find returns null when no entity of type T satisfies
// the predicate.
// ---------------------------------------------------------------------
// DbBase.Find returns null when there is no match.
[Fact]
public void DbBase_Find_returns_null_when_no_match()
{
@@ -195,10 +157,7 @@ public class BeforeTests
Assert.Null(result);
}
// ---------------------------------------------------------------------
// (11) DbBase.Find filters by runtime type — an Order attached to the
// context does NOT match a Client predicate.
// ---------------------------------------------------------------------
// DbBase.Find only matches entities of type T.
[Fact]
public void DbBase_Find_ignores_non_matching_types()
{
@@ -210,9 +169,7 @@ public class BeforeTests
Assert.Null(result);
}
// ---------------------------------------------------------------------
// (12) DbBase.Find returns the FIRST matching entity only.
// ---------------------------------------------------------------------
// DbBase.Find returns the first match only.
[Fact]
public void DbBase_Find_returns_first_match()
{
@@ -228,10 +185,7 @@ public class BeforeTests
Assert.NotSame(second, result);
}
// ---------------------------------------------------------------------
// (13) DbBase.Find handles a null context gracefully — with no explicit
// context AND no singleton configured, it returns default (null).
// ---------------------------------------------------------------------
// DbBase.Find returns null when no context is available.
[Fact]
public void DbBase_Find_with_null_context_returns_default()
{
@@ -239,8 +193,7 @@ public class BeforeTests
Assert.Null(result);
}
// (13b) When no explicit context is passed, Find falls back to the
// DbBase.Context singleton instead of returning null.
// DbBase.Find falls back to DbBase.Context when db is null.
[Fact]
public void DbBase_Find_falls_back_to_Context_singleton_when_db_is_null()
{
@@ -262,9 +215,7 @@ public class BeforeTests
}
}
// ---------------------------------------------------------------------
// (14) Client.FindByName delegates to DbBase.Find and works correctly.
// ---------------------------------------------------------------------
// Client.FindByName delegates to DbBase.Find.
[Fact]
public void Client_FindByName_finds_by_name()
{
@@ -278,9 +229,7 @@ public class BeforeTests
Assert.Same(acme, result);
}
// ---------------------------------------------------------------------
// (15) Client.FindByName returns null when the name does not match.
// ---------------------------------------------------------------------
// Client.FindByName returns null when there is no match.
[Fact]
public void Client_FindByName_returns_null_when_not_found()
{
@@ -292,7 +241,7 @@ public class BeforeTests
Assert.Null(result);
}
// (15b) FindByName with no context argument uses the Context singleton.
// Client.FindByName uses DbBase.Context when db is omitted.
[Fact]
public void Client_FindByName_uses_Context_singleton_when_db_omitted()
{
@@ -314,12 +263,7 @@ public class BeforeTests
}
}
// ---------------------------------------------------------------------
// (16) The class-level DbBase.Context singleton can be used as the
// implicit context source for Find operations — the classic
// ActiveRecord pattern where any entity method reaches the shared
// context without parameter passing.
// ---------------------------------------------------------------------
// DbBase.Context can be passed as the context argument to Find.
[Fact]
public void DbBase_Context_singleton_is_used_in_Find()
{
@@ -329,9 +273,6 @@ public class BeforeTests
DbBase.Context = db;
// Query using the singleton instead of passing the context:
// (In practice, callers often do this to avoid threading db through
// every call — the whole point of the ActiveRecord leak.)
var queryResult = DbBase.Find<Client>(c => c.Name == "TargetCo", DbBase.Context);
Assert.NotNull(queryResult);
@@ -340,9 +281,7 @@ public class BeforeTests
DbBase.Context = null; // cleanup
}
// ---------------------------------------------------------------------
// (17) DbBase.FindRequired<T> finds the matching entity — same result as Find<T>.
// ---------------------------------------------------------------------
// DbBase.FindRequired returns the matching entity.
[Fact]
public void DbBase_FindRequired_T_finds_matching_entity()
{
@@ -357,10 +296,7 @@ public class BeforeTests
Assert.Same(globex, result);
}
// ---------------------------------------------------------------------
// (18) DbBase.FindRequired<T> throws ObjectNotFoundException when no match
// is found (the domain-specific lookup miss, not a BCL exception).
// ---------------------------------------------------------------------
// DbBase.FindRequired throws ObjectNotFoundException when there is no match.
[Fact]
public void DbBase_FindRequired_T_throws_when_no_match()
{
@@ -374,13 +310,8 @@ public class BeforeTests
Assert.Contains("no matching Client found", ex.Message);
}
// ---------------------------------------------------------------------
// (19) DbBase.FindRequired<T> throws with a useful message when no context is
// configured (both explicit null and singleton null).
//
// Deliberately InvalidOperationException, not ObjectNotFoundException:
// a missing context is a configuration error, not a lookup miss.
// ---------------------------------------------------------------------
// DbBase.FindRequired throws InvalidOperationException when no context is
// configured — InvalidOperationException, not ObjectNotFoundException.
[Fact]
public void DbBase_FindRequired_T_throws_when_no_context_configured()
{
@@ -393,9 +324,7 @@ public class BeforeTests
Assert.Contains("DbBase.Context", ex.Message);
}
// ---------------------------------------------------------------------
// (20) Client.FindByNameRequired finds the matching client by name.
// ---------------------------------------------------------------------
// Client.FindByNameRequired returns the matching client.
[Fact]
public void Client_FindByNameRequired_finds_by_name()
{
@@ -408,10 +337,8 @@ public class BeforeTests
Assert.Same(acme, result);
}
// ---------------------------------------------------------------------
// (21) Client.FindByNameRequired throws ObjectNotFoundException when no
// match — message includes name.
// ---------------------------------------------------------------------
// Client.FindByNameRequired throws ObjectNotFoundException when there is no
// match; the message includes the name.
[Fact]
public void Client_FindByNameRequired_throws_with_name_when_not_found()
{
@@ -425,9 +352,7 @@ public class BeforeTests
Assert.Contains("no matching Client found", ex.Message);
}
// ---------------------------------------------------------------------
// (22) Client.FindByNameRequired uses Context singleton when no context arg.
// ---------------------------------------------------------------------
// Client.FindByNameRequired uses DbBase.Context when no context is passed.
[Fact]
public void Client_FindByNameRequired_uses_Context_singleton()
{
@@ -447,11 +372,8 @@ public class BeforeTests
}
}
// ---------------------------------------------------------------------
// (23) Client.FindByNameRequired throws with a useful message when the
// singleton is not configured (no arg, no singleton).
// Stays InvalidOperationException: configuration error, not a miss.
// ---------------------------------------------------------------------
// Client.FindByNameRequired throws InvalidOperationException when no
// context is configured.
[Fact]
public void Client_FindByNameRequired_throws_with_context_hint_when_singleton_null()
{
@@ -463,4 +385,4 @@ public class BeforeTests
Assert.Contains("no DbContext configured", ex.Message);
Assert.Contains("DbBase.Context", ex.Message);
}
}
}