Move tests to separate directories, and document

Today, with the tests inside a `tests` intermingled with the
corresponding library's source code, we have a few problems:

- We have to be careful that wildcards don't end up with tests being
  built as part of Nix proper, or test headers being installed as part
  of Nix proper.

- Tests in libraries but not executables is not right:

  - It means each executable runs the previous unit tests again, because
    it needs the libraries.

  - It doesn't work right on Windows, which doesn't want you to load a
    DLL just for the side global variable . It could be made to work
    with the dlopen equivalent, but that's gross!

This reorg solves these problems.

There is a remaining problem which is that sibbling headers (like
`hash.hh` the test header vs `hash.hh` the main `libnixutil` header) end
up shadowing each other. This PR doesn't solve that. That is left as
future work for a future PR.

Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>

tests/unit/libstore/data/derivation/bad-old-version-dyn-deps.drv

@@ -0,0 +1 @@
+Derive([],[("/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep2.drv",(["cat","dog"],[("cat",["kitten"]),("goose",["gosling"])]))],["/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep1"],"wasm-sel4","foo",["bar","baz"],[("BIG_BAD","WOLF")])

tests/unit/libstore/data/derivation/bad-version.drv

@@ -0,0 +1 @@
+DrvWithVersion("invalid-version",[],[("/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep2.drv",["cat","dog"])],["/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep1"],"wasm-sel4","foo",["bar","baz"],[("BIG_BAD","WOLF")])

tests/unit/libstore/data/derivation/dynDerivationDeps.drv

@@ -0,0 +1 @@
+DrvWithVersion("xp-dyn-drv",[],[("/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep2.drv",(["cat","dog"],[("cat",["kitten"]),("goose",["gosling"])]))],["/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep1"],"wasm-sel4","foo",["bar","baz"],[("BIG_BAD","WOLF")])

tests/unit/libstore/data/derivation/dynDerivationDeps.json

@@ -0,0 +1,38 @@
+{
+  "args": [
+    "bar",
+    "baz"
+  ],
+  "builder": "foo",
+  "env": {
+    "BIG_BAD": "WOLF"
+  },
+  "inputDrvs": {
+    "/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep2.drv": {
+      "dynamicOutputs": {
+        "cat": {
+          "dynamicOutputs": {},
+          "outputs": [
+            "kitten"
+          ]
+        },
+        "goose": {
+          "dynamicOutputs": {},
+          "outputs": [
+            "gosling"
+          ]
+        }
+      },
+      "outputs": [
+        "cat",
+        "dog"
+      ]
+    }
+  },
+  "inputSrcs": [
+    "/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep1"
+  ],
+  "name": "dyn-dep-derivation",
+  "outputs": {},
+  "system": "wasm-sel4"
+}

tests/unit/libstore/data/derivation/output-caFixedFlat.json

@@ -0,0 +1,5 @@
+{
+  "hash": "894517c9163c896ec31a2adbd33c0681fd5f45b2c0ef08a64c92a03fb97f390f",
+  "hashAlgo": "sha256",
+  "path": "/nix/store/rhcg9h16sqvlbpsa6dqm57sbr2al6nzg-drv-name-output-name"
+}

tests/unit/libstore/data/derivation/output-caFixedNAR.json

@@ -0,0 +1,5 @@
+{
+  "hash": "894517c9163c896ec31a2adbd33c0681fd5f45b2c0ef08a64c92a03fb97f390f",
+  "hashAlgo": "r:sha256",
+  "path": "/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-drv-name-output-name"
+}

tests/unit/libstore/data/derivation/output-caFixedText.json

@@ -0,0 +1,5 @@
+{
+  "hash": "894517c9163c896ec31a2adbd33c0681fd5f45b2c0ef08a64c92a03fb97f390f",
+  "hashAlgo": "text:sha256",
+  "path": "/nix/store/6s1zwabh956jvhv4w9xcdb5jiyanyxg1-drv-name-output-name"
+}

tests/unit/libstore/data/derivation/output-caFloating.json

@@ -0,0 +1,3 @@
+{
+  "hashAlgo": "r:sha256"
+}

tests/unit/libstore/data/derivation/output-deferred.json

@@ -0,0 +1 @@
+{}

tests/unit/libstore/data/derivation/output-impure.json

@@ -0,0 +1,4 @@
+{
+  "hashAlgo": "r:sha256",
+  "impure": true
+}

tests/unit/libstore/data/derivation/output-inputAddressed.json

@@ -0,0 +1,3 @@
+{
+  "path": "/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-drv-name-output-name"
+}

tests/unit/libstore/data/derivation/simple.drv

@@ -0,0 +1 @@
+Derive([],[("/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep2.drv",["cat","dog"])],["/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep1"],"wasm-sel4","foo",["bar","baz"],[("BIG_BAD","WOLF")])

tests/unit/libstore/data/derivation/simple.json

@@ -0,0 +1,25 @@
+{
+  "args": [
+    "bar",
+    "baz"
+  ],
+  "builder": "foo",
+  "env": {
+    "BIG_BAD": "WOLF"
+  },
+  "inputDrvs": {
+    "/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep2.drv": {
+      "dynamicOutputs": {},
+      "outputs": [
+        "cat",
+        "dog"
+      ]
+    }
+  },
+  "inputSrcs": [
+    "/nix/store/c015dhfh5l0lp6wxyvdn7bmwhbbr6hr9-dep1"
+  ],
+  "name": "simple-derivation",
+  "outputs": {},
+  "system": "wasm-sel4"
+}

tests/unit/libstore/data/nar-info/impure.json

@@ -0,0 +1,20 @@
+{
+  "ca": "fixed:r:sha256:1lr187v6dck1rjh2j6svpikcfz53wyl3qrlcbb405zlh13x0khhh",
+  "compression": "xz",
+  "deriver": "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-bar.drv",
+  "downloadHash": "sha256-FePFYIlMuycIXPZbWi7LGEiMmZSX9FMbaQenWBzm1Sc=",
+  "downloadSize": 4029176,
+  "narHash": "sha256-FePFYIlMuycIXPZbWi7LGEiMmZSX9FMbaQenWBzm1Sc=",
+  "narSize": 34878,
+  "references": [
+    "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-bar",
+    "/nix/store/n5wkd9frr45pa74if5gpz9j7mifg27fh-foo"
+  ],
+  "registrationTime": 23423,
+  "signatures": [
+    "asdf",
+    "qwer"
+  ],
+  "ultimate": true,
+  "url": "nar/1w1fff338fvdw53sqgamddn1b2xgds473pv6y13gizdbqjv4i5p3.nar.xz"
+}

tests/unit/libstore/data/nar-info/pure.json

@@ -0,0 +1,9 @@
+{
+  "ca": "fixed:r:sha256:1lr187v6dck1rjh2j6svpikcfz53wyl3qrlcbb405zlh13x0khhh",
+  "narHash": "sha256-FePFYIlMuycIXPZbWi7LGEiMmZSX9FMbaQenWBzm1Sc=",
+  "narSize": 34878,
+  "references": [
+    "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-bar",
+    "/nix/store/n5wkd9frr45pa74if5gpz9j7mifg27fh-foo"
+  ]
+}

tests/unit/libstore/data/path-info/impure.json

@@ -0,0 +1,16 @@
+{
+  "ca": "fixed:r:sha256:1lr187v6dck1rjh2j6svpikcfz53wyl3qrlcbb405zlh13x0khhh",
+  "deriver": "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-bar.drv",
+  "narHash": "sha256-FePFYIlMuycIXPZbWi7LGEiMmZSX9FMbaQenWBzm1Sc=",
+  "narSize": 34878,
+  "references": [
+    "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-bar",
+    "/nix/store/n5wkd9frr45pa74if5gpz9j7mifg27fh-foo"
+  ],
+  "registrationTime": 23423,
+  "signatures": [
+    "asdf",
+    "qwer"
+  ],
+  "ultimate": true
+}

tests/unit/libstore/data/path-info/pure.json

@@ -0,0 +1,9 @@
+{
+  "ca": "fixed:r:sha256:1lr187v6dck1rjh2j6svpikcfz53wyl3qrlcbb405zlh13x0khhh",
+  "narHash": "sha256-FePFYIlMuycIXPZbWi7LGEiMmZSX9FMbaQenWBzm1Sc=",
+  "narSize": 34878,
+  "references": [
+    "/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-bar",
+    "/nix/store/n5wkd9frr45pa74if5gpz9j7mifg27fh-foo"
+  ]
+}