Create missing parent directories for FileContent

[Steve Lee (SteveL-MSFT)]

Microsoft.Filesystem.File/Content currently fails when a file's parent path does not exist. This change makes the declarative ensure-present behavior create the required directory hierarchy automatically.

• Create missing parent directories when _exist is true or omitted.
• Keep _exist: false removal behavior unchanged and avoid adding an imperative force property.
• Emit a localized DSC-compatible INFO message before directory creation and a specific error if creation fails.
• Document the behavior and cover explicit and omitted _exist cases.

Tests: Focused FileContent set Pester tests (4 passed).

Fixes: #1728

[Copilot]

Copilot review overview

🟡 Changes recommended

Add coverage for failures caused by an existing file blocking a parent directory.

Get a fresh assessment by requesting another Copilot review.

Review effort: Lite
Findings: 1

Open (1)

• Add test for file-blocked parent directory creation failure · New

What changed in this PR

Updates Microsoft.Filesystem.File/Content to create missing parent directories during ensure-present operations.

Changes:

• Creates parent directory hierarchies before writing files.
• Adds localized informational and error messages.
• Documents and tests explicit and omitted _exist behavior.

File	Description
resources/​filecontent/​tests/​filecontent_set.tests.ps1	Tests directory creation scenarios.
resources/​filecontent/​src/​file.rs	Creates missing parent directories.
resources/​filecontent/​locales/​en-us.toml	Adds localized messages.
resources/​filecontent/​filecontent.dsc.resource.json	Documents directory creation behavior.

---

💡 Configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[github-actions]

😁 Code Coverage Report

Changed Code Coverage

93% (90%+ coverage)

Metric	Value
Changed lines analyzed	16
Lines covered by tests	15
Coverage percentage	93%

🔵 Full Codebase Coverage

82% (good)

Metric	Value
Total executable lines	19485
Lines covered by tests	16155
Coverage percentage	82%

Changed code coverage measures only Rust lines added/modified in this PR.
Full codebase coverage measures all instrumented Rust lines across the project.

[Copilot]

Copilot review overview

🔵 Needs a closer look

An exact parent path that is a file bypasses the new directory-creation error handling.

Review effort: Balanced
Findings: None

Resolved since last review (1)

• Add test for file-blocked parent directory creation failure

Previously missed (1)

In code that hasn't changed since last review

Validate parent path is a directory before writing

resources/​filecontent/​src/​file.rs:43

Checking only exists() treats a regular file at the exact parent path as a valid parent. For a target such as <root>/blocked/file.txt where <root>/blocked is a file, this skips create_dir_all and falls through to the generic write error instead of the new parent-directory diagnostic. Check whether the parent is a directory so this conflict uses the intended creation failure path; the negative test should also exercise this exact-parent case.