test-design.md

Test Design

Test plan for verifying the correctness and effectiveness of the hashline plugin integration with OpenCode. Covers 31 scenarios across 8 test files.

Test Matrix

A. Basic Edit Operations (6 scenarios)

#	Scenario	Operation	Expected Result	Verified
A1	Replace single line	SWAP 2.=2: with 1 body line	Line 2 replaced, others unchanged	✅
A2	Replace multiple lines	SWAP 2.=4: with 3 body lines	Lines 2-4 replaced by 3 lines	✅
A3	Delete line range	DEL 3.=5	Lines 3-5 deleted, no body	✅
A4	Insert before anchor	INS.PRE 3: with body	Body inserted before line 3	✅
A5	Insert after anchor	INS.POST 2: with body	Body inserted after line 2	✅
A6	Insert head and tail	INS.HEAD: + INS.TAIL:	Lines inserted at file start and end	✅

B. Tag Validation & Security (5 scenarios)

#	Scenario	Operation	Expected Result	Verified
B1	Correct tag	read → edit with returned tag	Edit succeeds, new tag returned	✅
B2	Stale tag	read → external modification → edit with old tag	MismatchError, re-read prompt	✅
B3	Fabricated tag	Edit with random 4-hex tag	Rejected: hash not from this session	✅
B4	Chained edits	edit → use returned new tag → edit again	Second edit succeeds	✅
B5	Missing tag	[foo.ts] without #TAG suffix	Rejected: missing snapshot tag	✅

C. Read Hook Injection (2 scenarios)

#	Scenario	Operation	Expected Result	Verified
C1	Normal file read	Read an existing file	Output has [path#XXXX] header	✅
C2	Non-existent file	Read a missing path	No tag injected	✅

D. Multi-hunk & Multi-file (3 scenarios)

#	Scenario	Operation	Expected Result	Verified
D1	Single file, multiple hunks	3 non-adjacent hunks in one section	All applied using original line numbers	✅
D2	Multiple file sections	2 [path#TAG] sections for different files	Both files edited, all-or-nothing	✅
D3	Same-path merge	Consecutive sections targeting same file	Merged into one section	✅

E. Error Handling (6 scenarios)

#	Scenario	Operation	Expected Result	Verified
E1	Line out of bounds	SWAP 100.=200: (file has 5 lines)	Error: line does not exist	✅
E2	Empty insert body	INS.POST 3: with no body	Error: empty insert	✅
E3	Delete with body	DEL 3.=5 followed by +text	Error: delete takes no body	✅
E4	Minus rows rejected	Body contains -old content	Error: minus row rejected	✅
E5	Unified diff contamination	First line @@ -1,3 +1,3 @@	Error: unified-diff hunk header	✅
E6	apply_patch contamination	*** Update File:foo.ts	Error or auto-strip	✅

F. Recovery & Drift (3 scenarios)

#	Scenario	Operation	Expected Result	Verified
F1	External write recovery	read → external change → edit unchanged line	3-way merge succeeds, warning emitted	✅
F2	Unrecoverable drift	read → external rewrite → edit missing anchor	MismatchError, re-read prompt	✅
F3	Head/tail + stale tag	read → external change → INS.HEAD: / INS.TAIL:	Succeeds with drift warning	✅

G. Line Endings & Encoding (3 scenarios)

#	Scenario	Operation	Expected Result	Verified
G1	CRLF file preserve	Read CRLF file → edit	CRLF preserved after edit	✅
G2	BOM file preserve	Read UTF-8 BOM file → edit	BOM preserved after edit	✅
G3	Trailing newline handling	File with trailing \n → delete last content line	Only content line deleted, format preserved	✅

H. Real-world Workflows (3 scenarios)

#	Scenario	Operation	Expected Result	Verified
H1	Chained refactoring	read → edit → edit → edit (3 rounds)	Each round tag refreshes, lines correct	✅
H2	Concurrent conflict	Agent A read → Agent B edit → Agent A edit	Agent A rejected, re-read prompt	✅
H3	Multi-file batch	One patch with 3 file sections	All succeed or all fail (atomic)	✅

Test File Mapping

Test File	Scenarios	Focus
tests/core-patch.test.ts	A1-A6, D1-D3, E1-E6	Core patch operations, multi-hunk, error handling
tests/core-tag.test.ts	B1-B5	Tag validation and security
tests/core-recovery.test.ts	F1-F3	3-way merge recovery from file drift
tests/core-format.test.ts	G1-G3	Line endings, BOM, encoding
tests/hook-read.test.ts	C1-C2	Read output snapshot injection
tests/tool-edit.test.ts	B1, B2, B4, E1-E6	Edit tool integration via ToolContext
tests/workflow.test.ts	H1-H3	End-to-end agent workflows