fix(python): 'create' and 'init' use warnings instead of errors for non-fatal pyproject.toml issues (#406)

* fix: use warnings instead of errors for non-fatal pyproject.toml issues

When installPyProjectToml encounters missing structure (no [project]
section, no dependencies array, invalid TOML, or file not found), these
are not true errors — they just mean the pyproject.toml doesn't have the
structure needed to auto-add slack-cli-hooks. The CLI now logs a debug
warning and returns a descriptive "Skipped updating pyproject.toml
because <reason>" message instead of propagating an error. True errors
(file write failures, pip install failures) remain errors.

* test: remove duplicate tests

* Update internal/runtime/python/python.go

Co-authored-by: Eden Zimbelman <eden.zimbelman@salesforce.com>

---------

Co-authored-by: Eden Zimbelman <eden.zimbelman@salesforce.com>

Author: mwbrooks

internal/runtime/python/python.go

@@ -216,12 +216,13 @@ func installRequirementsTxt(fs afero.Fs, projectDirPath string) (output string,
 }
 
 // installPyProjectToml handles adding slack-cli-hooks to pyproject.toml
-func installPyProjectToml(fs afero.Fs, projectDirPath string) (output string, err error) {
+func installPyProjectToml(ctx context.Context, ios iostreams.IOStreamer, fs afero.Fs, projectDirPath string) (output string, err error) {
 	pyProjectFilePath := filepath.Join(projectDirPath, "pyproject.toml")
 
 	file, err := afero.ReadFile(fs, pyProjectFilePath)
 	if err != nil {
-		return fmt.Sprintf("Error reading pyproject.toml: %s", err), err
+		ios.PrintDebug(ctx, "Warning: could not read pyproject.toml: %s", err)
+		return "Skipped updating pyproject.toml because file cannot be read", nil
 	}
 
 	fileData := string(file)
@@ -235,25 +236,26 @@ func installPyProjectToml(fs afero.Fs, projectDirPath string) (output string, er
 	var config map[string]interface{}
 	err = toml.Unmarshal(file, &config)
 	if err != nil {
-		return fmt.Sprintf("Error parsing pyproject.toml: %s", err), err
+		ios.PrintDebug(ctx, "Warning: could not parse pyproject.toml: %s", err)
+		return "Skipped updating pyproject.toml because invalid TOML", nil
 	}
 
 	// Verify `project` section and `project.dependencies` array exist
 	projectSection, exists := config["project"]
 	if !exists {
-		err := fmt.Errorf("pyproject.toml missing project section")
-		return fmt.Sprintf("Error updating pyproject.toml: %s", err), err
+		ios.PrintDebug(ctx, "Warning: pyproject.toml missing [project] section")
+		return "Skipped updating pyproject.toml because project section missing", nil
 	}
 
 	projectMap, ok := projectSection.(map[string]interface{})
 	if !ok {
-		err := fmt.Errorf("pyproject.toml project section is not a valid format")
-		return fmt.Sprintf("Error updating pyproject.toml: %s", err), err
+		ios.PrintDebug(ctx, "Warning: pyproject.toml [project] section is not a valid format")
+		return "Skipped updating pyproject.toml because project section invalid", nil
 	}
 
 	if _, exists := projectMap["dependencies"]; !exists {
-		err := fmt.Errorf("pyproject.toml missing dependencies array")
-		return fmt.Sprintf("Error updating pyproject.toml: %s", err), err
+		ios.PrintDebug(ctx, "Warning: pyproject.toml missing dependencies array in [project] section")
+		return "Skipped updating pyproject.toml because dependencies missing", nil
 	}
 
 	// Use string manipulation to add the dependency while preserving formatting.
@@ -264,8 +266,8 @@ func installPyProjectToml(fs afero.Fs, projectDirPath string) (output string, er
 	matches := dependenciesRegex.FindStringSubmatch(fileData)
 
 	if len(matches) == 0 {
-		err := fmt.Errorf("pyproject.toml missing dependencies array")
-		return fmt.Sprintf("Error updating pyproject.toml: %s", err), err
+		ios.PrintDebug(ctx, "Warning: pyproject.toml dependencies array could not be located")
+		return "Skipped updating pyproject.toml because dependencies missing", nil
 	}
 
 	prefix := matches[1]  // "...dependencies = ["
@@ -347,16 +349,20 @@ func (p *Python) InstallProjectDependencies(ctx context.Context, projectDirPath
 	// Handle requirements.txt if it exists
 	if hasRequirementsTxt {
 		output, err := installRequirementsTxt(fs, projectDirPath)
-		outputs = append(outputs, output)
+		if output != "" {
+			outputs = append(outputs, output)
+		}
 		if err != nil {
 			errs = append(errs, err)
 		}
 	}
 
 	// Handle pyproject.toml if it exists
 	if hasPyProjectToml {
-		output, err := installPyProjectToml(fs, projectDirPath)
-		outputs = append(outputs, output)
+		output, err := installPyProjectToml(ctx, ios, fs, projectDirPath)
+		if output != "" {
+			outputs = append(outputs, output)
+		}
 		if err != nil {
 			errs = append(errs, err)
 		}

internal/runtime/python/python_test.go

@@ -229,7 +229,13 @@ dependencies = ["pytest==8.3.2"]`,
 	}
 	for name, tc := range tests {
 		t.Run(name, func(t *testing.T) {
+			ctx := slackcontext.MockContext(t.Context())
 			fs := slackdeps.NewFsMock()
+			os := slackdeps.NewOsMock()
+			os.AddDefaultMocks()
+			cfg := config.NewConfig(fs, os)
+			ios := iostreams.NewIOStreamsMock(cfg, fs, os)
+			ios.AddDefaultMocks()
 			projectDirPath := "/path/to/project"
 
 			// Create pyproject.toml
@@ -240,7 +246,7 @@ dependencies = ["pytest==8.3.2"]`,
 			require.NoError(t, err)
 
 			// Test
-			output, err := installPyProjectToml(fs, projectDirPath)
+			output, err := installPyProjectToml(ctx, ios, fs, projectDirPath)
 
 			// Assertions
 			if tc.expectedError {
@@ -249,7 +255,9 @@ dependencies = ["pytest==8.3.2"]`,
 				require.NoError(t, err)
 			}
 
-			require.Contains(t, output, tc.expectedOutput)
+			if tc.expectedOutput != "" {
+				require.Contains(t, output, tc.expectedOutput)
+			}
 
 			// Verify file content contains expected strings
 			content, err := afero.ReadFile(fs, pyprojectPath)
@@ -527,29 +535,29 @@ dependencies = [
 			expectedOutputs: []string{"Updated requirements.txt"},
 			expectedError:   false,
 		},
-		"Error when pyproject.toml has no dependencies array": {
+		"Warning when pyproject.toml has no dependencies array": {
 			existingFiles: map[string]string{
 				"pyproject.toml": `[project]
 name = "my-app"`,
 			},
-			expectedOutputs: []string{"Error updating pyproject.toml: pyproject.toml missing dependencies array"},
-			expectedError:   true,
+			expectedOutputs: []string{"Skipped updating pyproject.toml because dependencies missing"},
+			expectedError:   false,
 		},
-		"Error when pyproject.toml has no [project] section": {
+		"Warning when pyproject.toml has no [project] section": {
 			existingFiles: map[string]string{
 				"pyproject.toml": `[tool.black]
 line-length = 88`,
 			},
-			expectedOutputs: []string{"Error updating pyproject.toml: pyproject.toml missing project section"},
-			expectedError:   true,
+			expectedOutputs: []string{"Skipped updating pyproject.toml because project section missing"},
+			expectedError:   false,
 		},
-		"Error when pyproject.toml is invalid TOML": {
+		"Warning when pyproject.toml is invalid TOML": {
 			existingFiles: map[string]string{
 				"pyproject.toml": `[project
 name = "broken`,
 			},
-			expectedOutputs: []string{"Error parsing pyproject.toml"},
-			expectedError:   true,
+			expectedOutputs: []string{"Skipped updating pyproject.toml because invalid TOML"},
+			expectedError:   false,
 		},
 	}
 	for name, tc := range tests {