Add more regex filters to installation docsgen (#2421)

Rather than handling these in individual providers, they're best served
here.

Adds a few test cases to guard against any regression.

- **Match TF mentions found in gitlab provider and add test cases**
- **Add a header to skip as seen in hcloud**

pkg/tfgen/installation_docs.go

@@ -398,14 +398,16 @@ func getDefaultHeadersToSkip() []*regexp.Regexp {
 		regexp.MustCompile("[Dd]ebugging"),
 		regexp.MustCompile("[Tt]erraform CLI"),
 		regexp.MustCompile("[Tt]erraform Cloud"),
+		regexp.MustCompile("Delete Protection"),
 	}
 	return defaultHeaderSkipRegexps
 }
 
 func getTfVersionsToRemove() []*regexp.Regexp {
 	tfVersionsToRemove := []*regexp.Regexp{
-		regexp.MustCompile(`It requires [tT]erraform [v0-9]+\.?[0-9]?\.?[0-9]? or later.`),
+		regexp.MustCompile(`(It|This provider) requires( at least)? [tT]erraform [v0-9]+\.?[0-9]?\.?[0-9]?( or later)?.`),
 		regexp.MustCompile(`(?s)(For )?[tT]erraform [v0-9]+\.?[0-9]?\.?[0-9]? and (later|earlier):`),
+		regexp.MustCompile(`A minimum of [tT]erraform [v0-9]+\.?[0-9]?\.?[0-9]? is recommended.`),
 	}
 	return tfVersionsToRemove
 }

pkg/tfgen/installation_docs_test.go

@@ -278,6 +278,34 @@ func TestApplyEditRules(t *testing.T) {
 			},
 			expected: []byte("This is a provider with an example.\nUse this code."),
 		},
+		{
+			name: "Strips mentions of Terraform version pattern 6",
+			docFile: DocFile{
+				Content: []byte("This provider requires at least Terraform 1.0."),
+			},
+			expected: []byte(""),
+		},
+		{
+			name: "Strips mentions of Terraform version pattern 7",
+			docFile: DocFile{
+				Content: []byte("This provider requires Terraform 1.0."),
+			},
+			expected: []byte(""),
+		},
+		{
+			name: "Strips mentions of Terraform version pattern 8",
+			docFile: DocFile{
+				Content: []byte("A minimum of Terraform 1.4.0 is recommended."),
+			},
+			expected: []byte(""),
+		},
+		{
+			name: "Strips mentions of Terraform version With Surrounding Text",
+			docFile: DocFile{
+				Content: []byte(readfile(t, "test_data/replace-terraform-version/input.md")),
+			},
+			expected: []byte(readfile(t, "test_data/replace-terraform-version/expected.md")),
+		},
 	}
 	for _, tt := range tests {
 		tt := tt

pkg/tfgen/test_data/replace-terraform-version/expected.md

@@ -0,0 +1,11 @@
+Use the GitLab provider to interact with GitLab resources, like
+users, groups, projects and more. You must configure the provider with
+the proper credentials before you can use it.
+
+The provider uses the [`xanzy/go-gitlab`](https://github.com/xanzy/go-gitlab) library
+to interact with the [GitLab REST API](https://docs.gitlab.com/ee/api/api_resources.html).
+
+Each data source and resource references the appropriate upstream GitLab REST API documentation,
+which may be consumed to better understand the behavior of the API.
+
+Use the navigation to the left to read about the valid data sources and resources.

pkg/tfgen/test_data/replace-terraform-version/input.md

@@ -0,0 +1,16 @@
+Use the GitLab provider to interact with GitLab resources, like
+users, groups, projects and more. You must configure the provider with
+the proper credentials before you can use it.
+
+The provider uses the [`xanzy/go-gitlab`](https://github.com/xanzy/go-gitlab) library
+to interact with the [GitLab REST API](https://docs.gitlab.com/ee/api/api_resources.html).
+
+This provider requires Terraform 1.0.
+
+Each data source and resource references the appropriate upstream GitLab REST API documentation,
+which may be consumed to better understand the behavior of the API.
+
+Use the navigation to the left to read about the valid data sources and resources.
+
+This provider requires at least [Terraform 1.0](https://www.terraform.io/downloads.html).
+A minimum of Terraform 1.4.0 is recommended.