Add tests for ocamllsp dev tool

Signed-off-by: Stephen Sherratt <stephen@sherra.tt>

test/blackbox-tests/test-cases/pkg/ocamllsp/dev-tool-ocamllsp-basic.t

@@ -0,0 +1,32 @@
+Test that the "dune tools exec ocamllsp" command causes ocamllsp to be
+locked, built and run when the command is run from a dune project with
+a lockdir containing an "ocaml" lockfile.
+
+  $ . ../helpers.sh
+  $ . ./helpers.sh
+
+  $ mkrepo
+  $ make_mock_ocamllsp_package
+  $ mkpkg ocaml 5.2.0
+
+  $ setup_ocamllsp_workspace
+
+  $ cat > dune-project <<EOF
+  > (lang dune 3.16)
+  > 
+  > (package
+  >  (name foo)
+  >  (allow_empty))
+  > EOF
+
+  $ make_lockdir
+  $ cat > dune.lock/ocaml.pkg <<EOF
+  > (version 5.2.0)
+  > EOF
+
+  $ dune tools exec ocamllsp
+  Solution for dev-tools.locks/ocaml-lsp-server:
+  - ocaml.5.2.0
+  - ocaml-lsp-server.0.0.1
+       Running 'ocamllsp'
+  hello from fake ocamllsp

test/blackbox-tests/test-cases/pkg/ocamllsp/dev-tool-ocamllsp-no-lock-dir.t

@@ -0,0 +1,15 @@
+Exercise the behaviour of "dune tools exec ocamllsp" when run in a
+dune project with no lockdir.
+
+  $ cat > dune-project <<EOF
+  > (lang dune 3.16)
+  > 
+  > (package
+  >  (name foo)
+  >  (allow_empty))
+  > EOF
+
+  $ dune tools exec ocamllsp
+  Error: Unable to load the lockdir for the default build context.
+  Hint: Try running 'dune pkg lock'
+  [1]

test/blackbox-tests/test-cases/pkg/ocamllsp/dev-tool-ocamllsp-no-ocaml-lockfile.t

@@ -0,0 +1,20 @@
+Exercise the behaviour of "dune tools exec ocamllsp" when the lockdir
+doesn't contain a lockfile for the "ocaml" package.
+
+  $ . ../helpers.sh
+
+  $ cat > dune-project <<EOF
+  > (lang dune 3.16)
+  > 
+  > (package
+  >  (name foo)
+  >  (allow_empty))
+  > EOF
+
+  $ make_lockdir
+
+  $ dune tools exec ocamllsp
+  Error: The lockdir doesn't contain a lockfile for the package "ocaml".
+  Hint: Add a dependency on "ocaml" to one of the packages in dune-project and
+  then run 'dune pkg lock'
+  [1]

test/blackbox-tests/test-cases/pkg/ocamllsp/dev-tool-ocamllsp-outside-dune-project.t

@@ -0,0 +1,17 @@
+Exercise the behaviour of "dune tools exec ocamllsp" when run outside
+of a dune project.
+
+
+This is necessary for dune to act as it normally would outside of a
+dune workspace.
+  $ unset INSIDE_DUNE
+
+Run the wrapper command from a temporary directory. With INSIDE_DUNE
+unset dune would otherwise pick up the dune project itself as the
+current workspace.
+  $ cd $(mktemp -d)
+
+  $ dune tools exec ocamllsp
+  Error: Unable to run ocamllsp as a dev-tool because you don't appear to be
+  inside a dune project.
+  [1]

test/blackbox-tests/test-cases/pkg/ocamllsp/dev-tool-ocamllsp-relock-on-ocaml-version-change.t

@@ -0,0 +1,63 @@
+Test that if the version of the "ocaml" package in the project's
+lockdir changes then the ocamllsp dev tool is re-locked to be built
+with the version of the ocaml compiler now in the project's
+lockdir. This is necessary because ocamllsp must be compiled with the
+same version of the ocaml compiler as the code that it's analyzing.
+
+  $ . ../helpers.sh
+  $ . ./helpers.sh
+
+  $ mkrepo
+  $ make_mock_ocamllsp_package
+  $ mkpkg ocaml 5.2.0
+  $ mkpkg ocaml 5.1.0
+
+  $ setup_ocamllsp_workspace
+
+  $ cat > dune-project <<EOF
+  > (lang dune 3.16)
+  > 
+  > (package
+  >  (name foo)
+  >  (allow_empty))
+  > EOF
+
+  $ make_lockdir
+  $ cat > dune.lock/ocaml.pkg <<EOF
+  > (version 5.2.0)
+  > EOF
+
+Initially ocamllsp will be depend on ocaml.5.2.0 to match the project.
+  $ dune tools exec ocamllsp
+  Solution for dev-tools.locks/ocaml-lsp-server:
+  - ocaml.5.2.0
+  - ocaml-lsp-server.0.0.1
+       Running 'ocamllsp'
+  hello from fake ocamllsp
+  $ cat dev-tools.locks/ocaml-lsp-server/ocaml.pkg
+  (version 5.2.0)
+
+We can re-run "dune tools exec ocamllsp" without relocking or rebuilding.
+  $ dune tools exec ocamllsp
+       Running 'ocamllsp'
+  hello from fake ocamllsp
+
+Change the version of ocaml that the project depends on.
+  $ cat > dune.lock/ocaml.pkg <<EOF
+  > (version 5.1.0)
+  > EOF
+
+Running "dune tools exec ocamllsp" causes ocamllsp to be relocked and rebuilt
+before running. Ocamllsp now depends on ocaml.5.1.0.
+  $ dune tools exec ocamllsp
+  The version of the compiler package ("ocaml") in this project's lockdir has
+  changed to 5.1.0 (formerly the compiler version was 5.2.0). The dev-tool
+  "ocaml-lsp-server" will be re-locked and rebuilt with this version of the
+  compiler.
+  Solution for dev-tools.locks/ocaml-lsp-server:
+  - ocaml.5.1.0
+  - ocaml-lsp-server.0.0.1
+       Running 'ocamllsp'
+  hello from fake ocamllsp
+  $ cat dev-tools.locks/ocaml-lsp-server/ocaml.pkg
+  (version 5.1.0)

test/blackbox-tests/test-cases/pkg/ocamllsp/dune

@@ -0,0 +1,3 @@
+(cram
+ (deps helpers.sh)
+ (applies_to :whole_subtree))

test/blackbox-tests/test-cases/pkg/ocamllsp/helpers.sh

@@ -0,0 +1,27 @@
+# Create a dune-workspace file with mock repos set up for the main
+# project and the ocamllsp lockdir.
+setup_ocamllsp_workspace() {
+  cat > dune-workspace <<EOF
+(lang dune 3.16)
+(lock_dir
+ (path "dev-tools.locks/ocaml-lsp-server")
+ (repositories mock))
+ (lock_dir
+  (repositories mock))
+(repository
+ (name mock)
+ (source "file://$(pwd)/mock-opam-repository"))
+EOF
+}
+
+# Create a fake ocaml-lsp-server package containing an executable that
+# just prints a message.
+make_mock_ocamllsp_package() {
+  mkpkg ocaml-lsp-server <<EOF
+install: [
+  [ "sh" "-c" "echo '#!/bin/sh' > %{bin}%/ocamllsp" ]
+  [ "sh" "-c" "echo 'echo hello from fake ocamllsp' >> %{bin}%/ocamllsp" ]
+  [ "sh" "-c" "chmod a+x %{bin}%/ocamllsp" ]
+]
+EOF
+}