ci: Install the built module from a local repository

.github/workflows/install-test.yml

@@ -0,0 +1,44 @@
+name: Install Test
+permissions:
+  contents: read
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+  workflow_dispatch:
+jobs:
+  # CI builds this module on every push but has never installed it, and a build cannot observe an
+  # install-time break - a RequiredModules entry naming a version that does not exist, or a
+  # dependency that was dropped from the manifest but is still needed. This workflow publishes the
+  # built module into a temporary file-share repository alongside mirrored copies of its required
+  # modules and then, in a process whose PSModulePath holds only an empty directory, saves and
+  # imports it. See psake/PowerShellBuild#229.
+  #
+  # It runs alongside the shared ModuleCI.yml call in test.yml rather than inside it, because the
+  # shared workflow is used by the whole psake organization and this check is specific to this
+  # repository for now.
+  #
+  # Both jobs run on windows-latest so that the same runner can host a real Windows PowerShell 5.1
+  # engine as well as PowerShell 7. What the test does and does not prove is documented at the top
+  # of tests/InstallTime/Invoke-LocalRepositoryInstallTest.ps1 - read that before treating a green
+  # run here as broader coverage than it is.
+  local-repository-install:
+    name: Local repository install (${{ matrix.editionName }})
+    runs-on: windows-latest
+    timeout-minutes: 30
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - editionName: PowerShell 7
+            probeEdition: PowerShell7
+          - editionName: Windows PowerShell 5.1
+            probeEdition: WindowsPowerShell
+    steps:
+      - uses: actions/checkout@v7
+
+      # The build and the publish are the same work for either edition, so this step always runs
+      # on PowerShell 7; only the isolated probe process runs on the edition under test.
+      - name: Install from a local repository
+        shell: pwsh
+        run: ./tests/InstallTime/Invoke-LocalRepositoryInstallTest.ps1 -ProbeEdition ${{ matrix.probeEdition }}

cspell.json

@@ -11,7 +11,11 @@
     ],
     "words": [
         "Authenticode",
+        "coreclr",
+        "fullclr",
+        "LASTEXITCODE",
         "psake",
+        "PSHOME",
         "MAML"
     ],
     "ignoreWords": [

instructions/repository-specific.instructions.md

@@ -42,6 +42,7 @@
 │   ├── psakeFile.ps1           # Tasks consumers import
 │   └── IB.tasks.ps1            # Invoke-Build entry (aliased as PowerShellBuild.IB.Tasks)
 ├── tests/                      # Pester 6+ tests
+│   ├── InstallTime/            # Local-repository install test (CI only; not Pester)
 │   └── TestModule/             # Sample module exercised by the test suite
 ├── build.ps1                   # Main build entry point for THIS repo
 ├── build.settings.ps1          # Build settings for THIS repo's own psake build
@@ -288,11 +289,27 @@
   `./build.ps1 -Task Test -Bootstrap` across a `ubuntu-latest`, `windows-latest`, `macOS-latest`
   matrix on PowerShell 7 and again on Windows PowerShell 5.1, and publishes the test results
 
+### Install test workflow (`.github/workflows/install-test.yml`)
+
+- Triggers: push to `main`, pull requests, manual dispatch
+- Runs on: `windows-latest`, once with a PowerShell 7 probe and once with a Windows
+  PowerShell 5.1 probe
+- Repository-local rather than part of the shared workflow, because the coverage is specific to
+  this repository for now (psake/PowerShellBuild#229)
+- Runs `tests/InstallTime/Invoke-LocalRepositoryInstallTest.ps1`, which publishes the built
+  module into a temporary file-share repository alongside mirrored copies of its
+  `RequiredModules`, then saves and imports it in a process whose `PSModulePath` holds only an
+  empty directory. A build cannot observe an install-time break; this can
+- Includes a negative control that republishes the module with an unsatisfiable dependency and
+  requires the save to fail, so a green run is evidence rather than an assumption
+- The comment-based help at the top of that script records what the test deliberately does not
+  cover — read it before treating a green run as broader coverage than it is
+
 ### Publish workflow (`.github/workflows/publish.yaml`)
 
 - Triggers: manual dispatch, GitHub release published
 - Runs on: `ubuntu-latest`
 - Reads `PSGALLERY_API_KEY` secret, converts to `PSCredential`, runs
   `./build.ps1 -Task Publish -PSGalleryApiKey $cred -Bootstrap`
 
 ## Repo-Specific Conventions
@@ -373,9 +390,9 @@
 | ------------------------- | ---------------------------------------------------- |
 | `$env:BHProjectPath`      | Repository root directory                            |
 | `$env:BHProjectName`      | Module name (from directory structure)               |
 | `$env:BHPSModulePath`     | Path to module source directory                      |
 | `$env:BHPSModuleManifest` | Path to `.psd1` manifest                             |
 | `$env:BHModulePath`       | Same as `BHPSModulePath`                             |
 | `$env:BHBuildSystem`      | Detected CI system (e.g., `GitHubActions`, `Unknown`)|
 | `$env:BHBranchName`       | Current git branch                                   |
 | `$env:BHCommitMessage`    | Latest git commit message                            |