feat: better error handling

Author: BuddhiLW

internal/tex/build.go

@@ -132,13 +132,21 @@ If no configuration file is provided, it will look for autopdf.yaml in the curre
 			}
 		}
 
-		// Ensure that the output file exists; if not, create an empty file.
+		// Ensure that the output file exists and isn't empty
 		if cfg.Output != "" {
-			if _, err := os.Stat(cfg.Output.String()); os.IsNotExist(err) {
-				if err := os.WriteFile(cfg.Output.String(), []byte{}, 0644); err != nil {
-					return configs.WriteError
+			// Check if output file exists
+			fileInfo, err := os.Stat(cfg.Output.String())
+			if err != nil {
+				if os.IsNotExist(err) {
+					log.Printf("Warning: Output file %s doesn't exist after compilation", cfg.Output.String())
+					// Don't create an empty file here - that would hide the real issue
+				} else {
+					log.Printf("Error checking output file: %s", err)
 				}
+			} else if fileInfo.Size() == 0 {
+				log.Printf("Warning: Output file %s exists but is empty", cfg.Output.String())
 			}
+			
 			// Use the provided output path
 			outputPDF = cfg.Output.String()
 		}

internal/tex/compile.go

@@ -73,25 +73,50 @@ func (c *Compiler) Compile(texFile string) (string, error) {
 
 	var cmd *exec.Cmd
 	// Create command to run
+	var cmdErr error
+	
 	if dirOutput == "." {
 		cmdStr := fmt.Sprintf("%s -interaction=nonstopmode -jobname=%s %s", engine, baseNameOutput, texFile)
 		cmd = exec.Command("sh", "-c", cmdStr)
 		log.Printf("Running command: %s", cmd.String())
-		if err := cmd.Run(); err != nil {
-			log.Printf("Error running command: %s", err)
+		cmdErr = cmd.Run()
+		if cmdErr != nil {
+			log.Printf("Warning: LaTeX command reported errors: %s", cmdErr)
+			// Don't return error yet - check if file was created
 		}
 	} else {
 		cmdStr := fmt.Sprintf("%s -interaction=nonstopmode -jobname=%s -output-directory=%s %s", engine, baseNameOutput, dirOutput, texFile)
 		cmd = exec.Command("sh", "-c", cmdStr)
 		log.Printf("Running command: %s", cmd.String())
-		if err := cmd.Run(); err != nil {
-			log.Printf("Error running command: %s", err)
+		cmdErr = cmd.Run()
+		if cmdErr != nil {
+			log.Printf("Warning: LaTeX command reported errors: %s", cmdErr)
+			// Don't return error yet - check if file was created
 		}
 	}
 
-	// Check if output PDF exists
-	if _, err := os.Stat(fmt.Sprintf("%s.pdf", outputPDF)); os.IsNotExist(err) {
-		return "", errors.New("PDF output file was not created")
+	// Normalize output path with .pdf extension
+	outputPDFWithExt := outputPDF
+	if !strings.HasSuffix(outputPDF, ".pdf") {
+		outputPDFWithExt = outputPDF + ".pdf"
+	}
+
+	// Check if output PDF exists and has content
+	fileInfo, statErr := os.Stat(outputPDFWithExt)
+	if statErr != nil {
+		if os.IsNotExist(statErr) {
+			// File doesn't exist, return the original command error
+			if cmdErr != nil {
+				return "", fmt.Errorf("PDF output file was not created: %w", cmdErr)
+			}
+			return "", errors.New("PDF output file was not created")
+		}
+		return "", fmt.Errorf("error checking output file: %w", statErr)
+	}
+	
+	// Check if file is empty
+	if fileInfo.Size() == 0 {
+		return "", errors.New("PDF output file was created but is empty")
 	}
 
 	return outputPDF, nil
@@ -188,4 +213,4 @@ var CompileCmd = &bonzai.Cmd{
 		}
 		return nil
 	},
-}
+}

pkg/api/funcs.go

@@ -52,14 +52,23 @@ func GeneratePDF(cfg *config.Config, template config.Template) ([]byte, error) {
 	// Build the pdf using the merged config
 	err = tex.BuildCmd.Do(nil, cfg.Template.String(), writer.Name())
 	if err != nil {
+		// First check if output file exists before trying to read it
+		if _, statErr := os.Stat(cfg.Output.String()); os.IsNotExist(statErr) {
+			return nil, err
+		}
+		
+		// Now check if file is empty
 		if futil.FileIsEmpty(cfg.Output.String()) {
 			return nil, err
 		}
-		// Normal to LaTeX to send build verbose info to stderr
-		// so we need to return the error only if the output file is empty
-		//
-		// To print the verbose "error" info, we need to print the stderr
-		// log.Println("Stderr while building pdf:", err)
+		
+		// If we get here, file exists and has content despite LaTeX errors
+		log.Printf("Warning: LaTeX reported errors but a PDF was produced: %v", err)
+	}
+
+	// Verify the file exists before attempting to read it
+	if _, statErr := os.Stat(cfg.Output.String()); os.IsNotExist(statErr) {
+		return nil, os.ErrNotExist
 	}
 
 	// Read the generated pdf
@@ -68,6 +77,16 @@ func GeneratePDF(cfg *config.Config, template config.Template) ([]byte, error) {
 		return nil, err
 	}
 
+	// Verify that the file is not empty and contains valid PDF data
+	if len(pdfBytes) == 0 {
+		return nil, os.ErrInvalid
+	}
+	
+	// Basic check for PDF header signature
+	if len(pdfBytes) < 5 || string(pdfBytes[0:5]) != "%PDF-" {
+		return nil, os.ErrInvalid
+	}
+
 	// Return the generated pdf
 	return pdfBytes, nil
 }